I would say very difficult. But not totally impossible. You would just need to get the minute distribution right and most difficult of all, have decent trainees. The problem with this approach is that you'll not take full advantage of quality trainees becuae you'll only be training them for 50% of the time respecitly.
It's more economically viable to get better trainees in one of either PG/SG or PF/C and train them every week. You'll be the best return on them in the long run. You can use older players of similar skills in the positions that you dont train which will therefore be cheaper.