Clans will be matched up based on the overall strength of its members. Strength is based on each member’s attacking power (troops, army camp capacity, spells and heroes) and defensive strength (defense buildings, walls, traps and heroes). 

Matchmaking will prioritize defensive capabilities in pairing Clans.  Powerful, late-game defenses and troops like Inferno Towers, Eagle Artillery and Grand Warden will have much greater matchmaking impact. 

Unlike the Multiplayer mode, trophies do not factor in when clans are matched.

Different layouts and base designs do not affect strength. The only way a member’s strength can be changed is if they upgrade their troops, defenses, spells, etc.

Finally, matchmaking will factor in Win/Loss records. This ensures that your opponents are worthy adversaries.