There are some cat abilities that dictate the meta and make basically everything except few compositions unviable. Doctor's 2nd skill makes all burn / posion squads absolutely useless.
Syllias' 3rd skill - if she does 10 shots, every cat of the same level on the battlefield dies. So every squad has to have very heavy CC, to stop her for at least 6 seconds.
And so, now pretty much everyone is building stun squad which contains - alice, meowboy, shelly, syllias, kitty wonka. In my league (plat4) everybody has at least 2 of mentioned, but most have 4+. Its not that interesting when there is only 1 meta build and everyone has it and in the end it all depends on who has higher levels.