At lower levels, yes. A good wiz team can wipe almost any base. At higher levels players know how to deal with that threat.
Pan Goli: Almost every top player has him on defense to delay Wiz teams with tower invulnerability. Also, the Pan enlightenment reduces Pan Goli invulnerability for the attacker.
Won Ton: Improves building shields and when shields pop, nearby enemies are slowed down.
Bullhead: Reduces Att of all enemy mercs (including wizards)
Rath: Decreases damage taken by all buildings during the first 30s of the attack.
Yes, these heroes help (A LOT), but it doesn’t necessarily mean a base without them is completely defenseless against wizards.
Recently flyer teams are gaining