Militia vs Church Home Group? Hmmm...
For purely pragmatic reasons, probably the Church Group. Because it's more likely to represent broader community interest, in terms of aims/goals and in terms of wider representation. Obviously, it doesn't represent
everyone (e.g., non-church members), but it's a keystone organization for a wider association of folks that inhabit a given geographical area and share certain beliefs & traits.
In other words, it's a Tribal gathering. And a cohesive Tribe is generally key to a successful communal survival effort. Mo' People = Mo' Bettah.
A Militia is an armed group organized for common defense and (to a lesser degree) for conduct of limited-means offense. Almost by definition limited to the number of volunteer military-aged combatants you can rustle up... and keep together long enough to be effective. A number that is going to be significantly less than the larger community-wide membership (all backgrounds, genders, ages) found in a church's membership.
A militia is merely a voluntary Action Cell organized to provide temporary armed response to limited eventualities.
A church group is a voluntary Community Association designed to provide years of consensus response to virtually any eventuality.
A large enough church group is perfectly capable of generating its own militia. But a militia is typically incapable of generating its own community.
-------------------------
With regards to the question of veterans making better militia material? Yeah, sure. In the event of a come-as-you-are party, people who've previously served in a hierarchical organization (military, police, first responders, workers union, etc.) are going to bring more to the table (and quicker) than those who never did.
Because their learning curve is shorter for self-organizing, planning, re-training, and executing operations. Regardless of technical experience (however dated), they already understand how the game is best played. Everything after that is a function of how much time they have to knock the rust off and sharpen the old edge. Or pick up new skills. Or refresh old ones.
If you decided to hold a pickup touch football game in the middle of some big community cookout/block party... which team would you bet on:
1. A bunch of randomly picked adults/teens without ball playing experience? Or...
2. A self-organized pickup team of former high school/college ball players?
That said, you could eventually bring the non-player team into pretty good form with enough physical conditioning, practice time, and good coaching. Especially if the former school players helped out in that training... and integrated themselves amongst the ranks of the inexperienced.
Militias can range from abysmal to superb. That's a function of motivation, experience, leadership, and dedication. As well as basic human material. Some militia groups are little more than social clubs. Some are dysfunctionally dangerous groups of armed & dressed-up buffoons. Some are actually effective small units (especially if they are heavily weighted with bona fide prior combat types).
Given time, resources, and structure, any militia can be professionalized and trained to an acceptable level of competence. From zeroes to heroes, just as long as they can stay together and improve upon prior successes. That was the very raison d'être for the job I did in the military. Raising, organizing, equipping, training, and leading surrogate indigenous forces to conduct combat operations. Something that has worked swimmingly well in several major wars conducted by the USA.
At my last swing at bat doing that job... we fielded ~8000 armed Iraqi SOF pipe-hitters, who were as good in a gun fight as
anyone on the planet. Very few of whom had prior military experience (or had even fired a gun) before joining. They were a form of militia who became gradually professionalized and increasingly lethal on the battlefield. Eventually becoming the the very best combatants on that chess board.
Before that, I was doing the same with Afghan tribesmen.
"Tribe": a social division in a traditional society consisting of families or communities linked by social, economic, religious, or blood ties, with a common culture and dialect, typically having a recognized leader.
Armed militia who served as coalition allies or paid mercenaries for US interests. Most of whom had never served a day in anyone's formal military. But all of whom were raised from birth as tribal fighters. Not unlike the warriors of any North American Indian tribe... or the early Minutemen/Militia of 18th Century Colonial America.
So, yeah, if I need to go do something armed tonight, tomorrow, or in just a very few days... I hope my little band is comprised of mostly former 11Bs, 0311s, etc. with recent GWOT combat experience. Because we can get back into the groove quickly, conduct time-constrained rehearsals, SOPs, battle drills, mission planning... and be off to the races with better than average chances of success. Or at least not get ourselves wiped out due to stupidity and lack of experience. Because we already understand the basics, understand the game, and understand our roles.
But give me several weeks or months with a crop of fresh faced 15-45 year-old cherries... and I can eventually deliver you a pretty fair armed & well organized maneuver element. One that will deliver the mail, get better with every confidence target, and not cut & run at the first shot.
Militia effectiveness is almost entirely dependent upon their being well led & trained. Something lacking in many modern day examples. Which is actually nothing new in the military history of militias through the ages. Just something to be understood and planned around.
A local self-identified Militia Group could be anybody. Dangerously anybody... and highly subject to the problem of toxic and hidden small group dynamics. Like moving in to board with a strange family that you actually know little about.
A local Church Group is a broader organization that
could be damn near everybody in a wider community. Easier to read, easier to develop consensus among, and easier to sway to common purposes. Those driven by universal need to protect families, community, and property. It provides a larger framework for accomplishment of community survival goals. Everything from raw labor and potential combatants to unique professional skills, local intelligence networking, and logistical support.
Best of both worlds would be a community supported local militia, perhaps initially recruited from the larger totality of a church membership (as well as its reliably vetted non-member neighbors).
As noted up-thread, there's hardly an overt "militia" in the land that isn't already infiltrated and collected on by law enforcement or intelligence agency circles. In some respects, treated exactly as the authorities treat any organized gang. Always watching to see if they can hem them up in some illegality that might stick in front of a grand jury.
Churches? A little bit less so. Churches tend to have influential local financial/power-broker membership. Community members unafraid to use lawyers. Some of them actually being lawyers. People tied together by both their faith and their long personal associations. And, in the case of a church congregation, a little more Constitutional protection extant than with self-declared militias.
During Unconventional Warfare training in places like Europe, I've encountered (and used to my benefit) both types of associations. Used organized church laity & clergy to accomplish certain things. Used long established (and extremely well vetted) WWII/Cold War veteran-comprised militias to accomplish other things.
Those militias were usually closed circles of folks who had known each other from wartime service, from growing up together, and from bringing in their sons & grandsons to continue the organization. You had to be long-standing local to join. And they
never advertised for membership nor showed their (armed) existence in public. Tribal Warrior Societies existing within larger Community Tribes.
Saw the same thing over in the Balkans after the 90s wars. Veterans Associations (militias) were the power groups behind many communities. In some cases, to the betterment of the local populace. In other cases, they'd just become militarily organized mafia... and ran everything in the background (including local government) as a criminal enterprise.
Interesting topic.