I hate painting penitent models and how to change that.

Okay so i bought my Sororitas army with a lot of people selling their combat patrol so i have a some repentias, archo lagellant and penitent engine. The problem is i abolutely love painting my sisters of battle but these penitent models ar always left aside and i cannot start to paint theme bescause they seem so weird to paint. I'd like to have a fully painted repentia and stuff them in a rhino to smash some heretics but every time in try to start painting one i feel very quickly bored/annoyed.
Do you know a easy way to paint some of those models or are you in the same position ?
(The penitent engine also seem to be a nightmare to paint with all the cables and hard access parts)