this would be interesting, but you're going to need to make it fast paced to keep players interested. A large-scale walk-places map wouldn't work well with single weapon loadouts but if you kept things to like some midair DM-style TDM, matches would be fast paced enough to have players cycle through different weapons quickly enough to make each match different.
I suggest you to mix up weapons from different packs, like medieval weapons, snipers, shotguns, pistols, knives, RC car, sentries, etc. Try to make each weapon used different from each other in terms of skill necessary to use them well. Like, have only one sniper, one shotgun, one pistol, and mix up raycast and projectile weapons so its not just one or the other. put in novelty weapons as well since this kind of dm is practically the only one appropriate for them.