Why do walls exist at all? Because that's the largest size pull the dungeon is designed for. So, actually, yes - Wall-to-wall pulls are part of the game's design. If they weren't, then the walls would be more frequent. Why allow tanks to pull two packs of mobs at all? Why do some walls end after two pulls, but some allow you to do three?

The mere fact of a wall's existence tells you everything you need to know about the intended pull size.