This thread is a black hole of over-analysis.
Eclipse Magus is post-Trigger Magus. Why should he be anything more? Kato is not out to confuse us even more than he has to.
Aren't there, in theory, two post-Trigger Magus, though? Radical Dreamers is still post-Trigger; it just happened in a different dimension. I think the accepted theory is it's a dimension in which Crono was never revived.
I mean, I get what you're saying, and you're probably right. There is no reason for Eclipse Magus to be Magil. The only basis for it is his change in personality, but honestly, we don't know from how far in the future Eclipse Magus came. He could have just naturally matured that way.
Additionally, since Chrono Cross effectively accomplished what Radical Dreamers set out to do(tie up loose ends in CT), there's no reason that RD should be reintroduced to what is considered canon. RD is just a sort of sidestory now.
So, yes, I concede that point, but I still think they're trying to make a Magus to Guile connection.