Currently playing a game as SB, and while you're absolutely right on his philosophical traits, I think you're exaggerating on the military end. Granted this isn't how all (or even most enemies are) but I just attacked Joao whose army is 100% longbows and catapults (Dog Soldier useless). My swords, cats, HAs and of course, Drill IV longbows, were able to take him easily, but the protective bonus was still minimal. While they didn't require any resources, their power is still quite low for their cost and they can't get city raider.
Also, about leaders being dependent on resources, as much as I like Philosophical, it is VERY happiness dependent. I have only sugar (and traded gold and wine), representation and 2 religions in most cities and its still very hard to get happy populations above 13.
But a Phi/Cha leader (aka Lincoln) has everything geared for a specialist economy that isn't excessively dependent on wonder building. And charismatic is also much more of a military trait than protective is.
Now if they made a Phi/Ind leader, the specialist economy would crush all competition...