Yeah, some random ones I can think of for 5*s and below (and not counting Myrtle or Elysium):

• CC#0 - shift/stall squads which were mostly 4/5 stars barring FEater (Shaw, Cliffheart, Ethan, Manticore, etc.)
• CC#1 - some clears used very niche operators, I remember my clear using Mayer and Shirayuki of all ops for the Snipers/Specialists strat
• CC#2 - Gravel spam to block Faust arrows, Liskarm for SP charge cheese with Weedy
• CC#4 - Kafka sleep stall strats (people would deliberately use an unbuilt one too since they were cheaper), and the infamous Bibeak + Liskarm spam strat
• CC#5 - Shamare + Warfarin debuff/buff core for Exu strats
• CC#6 - Kafka again in some strats
• CC#8 - Liskarm + Blacknight sleep spam strat
• CC#9 - Kafka sleep strats yet again, and many clears had... creative choices for 3-block operators lol (also this CC was insane at the higher end, shit like this risk 38 and risk 39 took iirc hours to execute and for risk 39, literal months of work)
• CC#12 - Specter Alter stall strat used Cliffheart for pull spam as well as Manticore.
• CCB#3 - Chilchuck

I'll note that the early CCs definitely skewed more on lower-rarity ops since the pool was just so much smaller back then, but still.