I guess you're right.
But my thinking is that although inside iso will try to make an open shot for big-men, I think it'd still be hard, as inside is usually well guarded with C and PF. In order for inside iso to work efficiently, I believe that the big-men need to be much much better than the opponent's big-men. If offense big-men were relatively better than the defense big-men, the big-men will still attempt many shots I guess, but if it was so, I doubt this tactic will work efficiently.
I don't really think inside iso and outside iso are very effective offensive tactics (but ofc it varies from teams to teams).