This is not true for tanks. Defensive Stats are only applicable to white damage and completely useless for yellow damage. Endurance is needed to soak yellow damage, and soak the white damage that passes through you defences. So with Defensive Stat augments coming with Power instead of Endurance, enhancements and mods are the places where Endurance is stacked.
Endo is important, but you get it in every other hilt, armoring, mod, and on 14x augments as well assuming you're stacking the primary stat ones. You can easily hit 23K without even trying very hard, and without using the endurance heavy enhancements anywhere, and that is all you should need to tank anything in the game. The marginal amount of added endo on the endo heavy enhancements is just a waste, and those points are better spent taking the ones that boost the stats instead. If you're hurting that bad for HP and really, really think you need it, then you're better off just going with Fortitude augments to buff that up, and still keeping stat heavy rather than endo heavy enhancements.