I still didn't think it was Clockwork on the previous page. The gear motif for a time master isn't exclusive to him- and I think it's fine you used it here since we're dealing with robots.
I agree with you that it's probably Rung. It makes sense for it to be him and I can't think of anyone else it would be. Maybe Rodimus would be a redhead, but Rodimus would totally be a frat boy, not this.