Both the Cavs and warriors have a hole in that they can't deal with good offensive bigs with center size. Both these teams are over relying on their power forwards to play the five and losing as a result.
Cavs loses
Magic - vucevic 23/7
Nets - ??
New orleans - Davis: 30/14 Cousins: 29/12/10
Knicks- porizingis: 32/12. Enes 18/12
Warriors loses pistons, grizzlies, rockets
It may be the case with the Cavs, but it's definitely not with the Warriors. And your theory doesn't even make any sense - Warriors lost to the Pistons and Drummond was 4 from 17 with 8 points, and largely ineffective, except on the glass (which he's strong at against most teams). Warriors lost to the Rockets (by .1 of second), and Capela isn't exactly a "good offensive big", and he was largely ineffective for that game, only playing 18 minutes.
Basically, their only loss against a "good offensive big" that actually played well, was Memphis.
The Warriors have one of the best and most versatile defensive frontcourts in the league (Draymond, ZaZa, Durant, West, and McGee - even Iggy can defend at the 4), it's not that they can't deal with team who have good offensive bigs, it's that they've been inconsistent on the defensive end, in general.
Bradley and Reggie both went for 20+ points on high percentages in the Pistons win over the Warriors
Harden, Tucker and Gordon went for 20+ points on mostly high percentages in the Rockets win over the Warriors