No, most clans really don't have to kick inactive members to pass.

If you kick 15, your clan is 100% active. That's just how the math works. But you really don't have to do that, unless your clan has like 1 active member out of 30 (as long as your post on the board often enough and play a few wars)

As I've said many times before, if your clan is so inactive in general that only, let's say 4 out of 30 members are active, then maybe you don't need square tags and a board.