Well doing Invader this way is infinitely easier than doing Synapse/Citadel/Numina on Hero side, wow. I literally just got done doing the accolades the other day on my main tanker.
That said, one small thing that'll help:
Actually in Striga Isle if you wait around until dark, the Warwolf mobs become Vampyre mobs. You can still do both very easily in Striga and especially if you grab a friend who also needs the accolade, it'll take you about 20 minutes to do both. Just did this the other day.