Hey Greg the wild rider has the walker ability, but the other bikes don't. Based on your comments above I assume walker isn't meant to be there? Personally I like the idea of the bikes all getting walker, as I find them a little underwhelming at times compared to core options in other lists. But I'm not the best tactician around

I'm not really up to speed on the other craft worlds. Do their signature units get rule or stat differences, or are the changes largely compositional and cosmetic as well?