I did this season(5 Rounds) on 1 front and 2 rear Dunlop slicks only. Finished 3rd in both AM600 and Lost Era. I only seem to spin the rear a lot on modified track and don't push the front often.
I had to replace the front at Round 2 because something in the sidewall broke and it bulged out real weird. Last season I went 5 rounds on an already scrubbed front until I replaced it(still had loads or rubbed but wouldn't turn worth a damn anymore). I replaced the rears every 3 rounds but have only ever had one go off really bad in a race which did cost me a win imo.
Can't really say what I do right or wrong as I don't seem to use anywhere near as many tires as a lot of other people but it seems to work for me. I don't ever do friday practice and only usually go out for one or two sessions of practice on Sat/Sundays so that could be part of it.
Or all of the reason. If you don't turn laps you won't use rubber.