They are best paired with tanks. However, they are Mini - Tanks themselves.
Using tanks to protect them is a very good idea, they can freeze defenses, keeping the other units alive longer while it lives longer.
Paired with healers and a GoWiPe army, it can be extremely deadly.
Using a Snowball Wizard with the flare spell, you can send it to the second layer or, if using it properly, you can send it to the TH. Remember to freeze the Inferno Towers,. By the time they unfreeze, they should be slowed and should be missing 1 quarter of it's HP.