A lot of other people complained after last update that heroes refused to break walls and go into core, instead wandering around it.
Can't have one without the other:
- Either troops do attack walls and thus are more likely to break into the base
- Or troops avoid walls and more frequently walk around the base, or even back track to go outside
Can't make the AI do both, choose to break walls when you like to and avoid breaking walls when you don't want them to. AI can't read your mind, it can't be programmed.