I understand vanguard, but won't it only come into play when attacking? (so it's not useful to a creature with defender). Also, creatures with Vanguard should have higher toughness or damage-prevention abilities to be useful right? 1 life doesn't really do much.

hmm it also comes into play blocking. so like opponent has a 3/2 attacking and you double-block with a 1/3 vanguard and 1/1. The opponent must assign three damage to the vanguard creature and your 1/1 survives

but you're right. I assigned the P/T before I put the abilities up