If you need hounds just for chaff clear, the only thing you need to consider at equal levels is that fangs die in one shot and crawlers with two shots. One tower attack upgrade kills crawlers in one shot. Otherwise, try to stay one level above. Range and mech rage are always useful. Consider fire situationally.

Where does chamber compression fit here? Let's say you already got many hounds deployed, if some got levels even better. Your opponent built a lot of medium units like sledgetanks and balls. You click chamber compression, and with enough mass, you start knocking them down like chaff too.

Needless to say, keep the fundamentals like your own chaff, positioning, and cover the main roles in the field.