Not sure how anti FotM as Stone/rad is listed as 27th most popular tanker and 5th most popular stone armor combo. It is however incredibly tough.
Through IOs have incarnate soft capped def to SLFC, mid 50s def to EN, 30% psi.
Hard capped resist to all but psi which is at approx 80% it can be capped but at the cost of alot of psi def which is more useful as the psi attacks come with -recharge.
Rad attack comes with a good self heal a second damage aura. Radioactive smash with a force feedback proc goes someway to helping with the recharge problems as does running between mobs with ninja run giving time with out granite's -recharge.
I tried to make the most survivable tank possible with darkest night from the patron pools, void judgement the regen incarnate heal it's unlikable.
I considered DM for its heal or ice sand stone for KD control but thought rad had the best combo of them.