The last two turns are built for warrior tanks. The tank killer moves all come out in 50s~1 minute intervals, meaning a warrior can blow something nice pretty much every time he has to tank them. However, warrior performance on turn 3 and 4 shouldn't matter to this guy or your group, because you need to get past turn 2. Even if the fight is doable for your party without Storm's Path, the cushion it provides is enough to justify taking a warrior. Storm's Eye for the ninja is just icing on the cake.

TrivariumOri basically summed up my thoughts: it's concerning that you said he wants to play paladin because it's lazier/easier and then he only pulls 130 dps. Even for full time Shield Oath that seems very low, especially if the ninja was keeping up the slashing debuff.