New here, but not to multiboxing. Here are my D3 setups :)

[Devile]

I gave up on mixed parties for now since at least for 2.1.2 GR they are very inefficient. For group play is way better but not for multiboxing unless u find a way to micro each char easily without making them stop attacking and/or die. DHs are by far the class that does the highest burst damage but they die in 1 in GR40+. A tiki WD will do NOTHING to save them. There are a ton of mobs that will annihilate them before the WD CCs, not to mention all the annoying Elite effects there are. If there was a way to have formations in D3, by all means, mixed party would be the way to go for multiboxing.

The whole point of a zDPS char is to have CC and boost your party DPS, but if u pick a class that doesn't have high burst damage, what's the point? The zDPS will boost low damage so overall u won't benefit much compared to having all 4 chars of the same class. If it's for permaCC, some/most classes have a way to permaCC with 4x chars (or close to). Obviously some are better than others. I rather do this instead of mixing classes and adding a zDPS char to the party. So far to me, it only makes sense if u have DHs but survivability is a huge issue there.

4x Crusaders has worked the best for me, followed by 4x monks. I'm sure I can do GR50+ with my DHs if I get REALLY lucky with mobs and elites affixes but whats the point? It will not be a real scenario since getting easy white mobs + easy elites + good map layout is like a 1% chance. There's no mix I found with DHs that worked in GR43+, they just die over and over. Crusaders are tanky and can do very good at higher GR but they don't have very high burst damage. Adding a different class will add debuffs but I'll lose laws uptime which will hurt me more overall.

2.2 adds certain items that will change a lot of things, making mixed parties a lot more appealing. But right now, I don't see a setup that can be competitive in GR with mixed classes. My objective is not breaking records, but just upgrading my gems to higher levels and be able to do faster GR35 for exp.