I usually have 9-10 athletics and 12-15 strength. I also fight in strat battles pretty often.
Strat battles tend to be much more team-oriented with everyone fighting in close quarters and lines where strongfats dominate, so most commanders don't make it a point to bring equipment for players with under 15 strength because they're uncommon in strat. With 12 strength you'll probably join some battles where there aren't any weapons in your class that you meet the requirements for, and if there are it was probably incidental. The same goes for armor, although there's usually at least some light armor for archers to wear. If there are weapons and armor that you can use, there usually isn't much of it and your side could run out before the end of the battle. I usually get accepted because I can do reasonably well even if I'm naked half the time and scavenging weapons, but that's the exception rather than the rule.
Honestly it's a different beast altogether and what works in NA_1 won't necessarily work in strat. It's like cRPG's hardcore mode. Your best bet is to go in with at least 15 strength, no ego, and just do whatever the boss-man says. Get a few kills, try not to die too much, and learn as you go.
P.S. avoid fighting in castles as an agility build, trust me.
