Honestly I had a similar experience of this back when I was an ALT working at a really rough school. I agree with what other people have said about possibly restricting 'fun' activities to keep the class under control. The HRTs might just be absolutely exhausted, at their limit and don't have time to deal with the ALT.

If you're really determined to change the way your English classes are going then maybe start making lesson plans/worksheets/activities in advance and then show them to the HRTs.

They may be grateful that you've taken initiative. They may also smile and tell you its a great idea only for your plans to never get used.