EQ has a major power creep problem. Once AA were introduced, the game had to be balanced around that rather than stats and gear. With players at the same level stratified by AAs rather than just levels and gear, both mob floors and ceilings had to increase, so limiting your AA to the laughable floor of 250 will stop you at a wall. Eventually the mobs just have an exponential amount of HP your DPS can't chip away at in the time your tank will be smashed and/or healer will run out of mana.
Long ago, I read a good write up from a premier raiding guild on tank and healer mechanics in, likening tanking and healing to filling up a cup with holes in it. Without AA, your cup is too small to hold much water (effective HP) and the water you refill (healing) is insufficient to replace the water pouring out of the giant hole in the bottom (mob damage, missing avoidance, & mitigation from AAs) due to lacking those AAs. The wall is where you will fail because xp mobs will kill your tank before you kill them.
I am actually pretty amazed at some of the answers here for people hitting 85-90 FTP because of how hard of a wall the game threw at me in UF/HOT (80-85) where DB mobs turned my tank into paste even WITH KR because I wanted to jump straight from the last tier of defiant gear into UF/HoT T1. Even the move from TSS to SOD for quested gear, which was a step up from the defiant required much more attention than prior leveling. My tank has spent 95% of his time since 51 subscribed. After that initial hump, it was smooth sailing for my group, just capping levels with auto-granted AAs and moving on up to the next xpac.
If FTP no KR were a limitation, I would set additional limitations like capping my adventures to out leveling (70/75?) and then tackling raid mobs in POP/GoD/OoW since the mechanics of most POP raids and some GoD/OoW raids won't limit your ability to box them.
Feel free to prove me wrong, but cannot imagine the possibility of running a level-capped, strong, truly FTP group, even if you were PLed to 115/TOV. You might be able to find a combo that can kill LB/green mobs via cheese and copious time, but that doesn't fit the request of "strong."