Next steps

[MiRai]

So what should my next steps be in getting a multiboxing degree?

Is it worth building up a mixed 5 man team or should I be switching up to 10?

I guess you could just keep trying out different compositions while looking for their weaknesses, and then figuring out how to overcome those since 5 Mages probably don't have many of the weaknesses of a mixed-class team.

If all you've leveled is 5 Mages to 100, then I couldn't possibly recommend moving to 10 accounts (assuming that's what you mean by "switching up to 10"), unless, of course, all you want to play is 10 Mages.