User blog comment:Joseph416/The Hero Generation- Crossover/@comment-5542110-20120102090313/@comment-4137930-20120102194003

Multi-Guest stars would lead to multi-trixes. Too many Trixes in the episode would just lead to confusion. At this point, I'm already against the idea of Sem and Joe both having Trixes, because you won't be able to tell them apart once they're alien- they all have the popular 'omnitrix' symbol on their chests.