Maybe paint Th30's cheeks/intakes of his helmet dark grey as on SIEGE Springer's to break up the cohesive green a bit and shorten the neck on Th30's body and it will be perfect
thrilling 30 head on siege body doesn't look that bad. The other way round is REALLY weird looking, though.
Rotor/sword swap doesn't look to bad either. The green is almost the same and I like the generations sword better.