Precisely looking at your example I don't think Steelhelms are less customisable than those, but I get your point. Steelhelms is probably one of the most customisable kits they've released recently, and both can be mixed in the same way. Heads, hands, shield... even with Steelhelms you can customise more the body. I think they can charge more for two reasons. 1: Their IP placement, and 2: Their sculpts is ages above the Victrix one.