You just need a initial team of 5 level 60s geared properly. A team that covers some bases, generally a support or two, a dps or two, and a aoe decrease defense. 

There are massive difference between a 5 star champion and a fully leveled/masteried/booked 6 star champion. As well as having them geared appropriately.

I would focus on getting 12-3 brutal farmer, while doing the highest level dragon possible for 100% winrare.

Watch some hellhades f2p series, learn how to farm efficiently, and learn how to gear appropriately.

Haha, just checked Uugo again (she's developing currently), has a "couple" of those roles nailed down.  Cleanser, healer, de-DEF'er, Leech, possibly reviver, too.  Probably her, Deacon, and Coldheart were best 11 ancient shardpack crack-from-gems, I've yet got.  Like, Lazarius is amazing, especially getting him on 2nd primal, but it's pretty daunting other than masteries to upgrade him, I might leave him as a support member with his un-transformed state beyond ascending him.  I like that rares and epics can actually form a team core on a budget.  That's pretty cool.

Uugo isn't really all of that. She's mainly a debuffer. The other roles she can play, but generally as a secondary role. Eg, yes, she has leech, but it's single-target and not guaranteed to land. Simlarly, she can heal, but on a 4-turn cooldown, which is generally too long to be reliable. And her revive is extremely conditional.

Fair, but it will likely be some time yet before I find a better fit for early Dungeon/special raids.  For now, I see her -60% DEF debuff and cleaning having to be enough until I get better depth options as at least one member for Iron Twins. 😊 I mean, she's rated 4.5 overall on HH and decent to good in most areas.  I'll work with that.

Oh I'm not trying to diminsh her value. Just, don't expect her to keep your team alive in scenarios where you are taking a lot of damage.

On that note, I'm kind of forming an Arena team in my head.  Speed all as much as I can.  Lead off with Deacon or another accelerator, hit A2 on Uugo, A2 Lazarius Nest of Vipers (either Uugo or Lazarius should lock buffs for other team), then hit nuker (at this time Elhain but maybe later Kael once I get him).  I don't expect to conquer the world or anything, but going after battles in my team power range in Classic Arena would be fun for a change.

I currently have all of those slot holders in hand.  I also have Apothecary, and can farm Warmaiden and Spirithost.  Any lineup suggestions for Rare-Epics to aim for instead?

It does occur to me, though, to ascend Lazarius.  Then he can be the speed fixer, buffer with Rift Gaze or buff blocker.  Either way, oodles of options.

The biggest thing right now that annoys me is the sheer # of Kael/Sun Wukong teams.  Exhausting! 😁

I just straight-up avoid Ronda/UDK schizz, but Kael/Sun Wukong feels like something I should be better at taking down.