For anyone playing Dota Underlords, it's pretty evident that the meta hinges on just a few compositions. That does get a little stale, but it does also mean that if you're wanting to climb to higher ranks, it's fairly easy not to fail. Here's the best 3 in the current meta.
6 Knights + Trolls
Pros
Super easy to play.
Pretty hard to lose with.
Comes online incredibly quickly.
Has very few counters (if any).
Your last pick can pretty much be anything.
Cons
Everyone wants Knight units. You'll have to fight for them.
Trolls, similarly to Knights, are also sought after.
Assassins are probably their weakest.
6 Hunters + 3 Warriors
Pros
Most of the front-line are meta units, capable of carrying any match.
Massive, rapid damage.
Your front-line pretty much gaurentees your backline goes untouched.
Your 10th unit is totally variable.
Cons
Most of the units are late tier.
You'll often lose early game to Assassin compositions.
Knights give you a run for your money.
6 Assassins + 3 Elusive
Pros
Amazing burst potential.
One of the few compositions that can handle Knights.
Can snowball early game if you land lucky with upgrades.
It's a fun build to run.
Cons
Easily countered by Knights/Warriors bunkering in a corner.
You'll go on a losing streak for a long time before your units come online.
To gain the Elusive bonus, you need a little bit of luck (Treant is popular).
Can be tough to gain 6 Assassins, especially if fighting for them against someone else.