Yup, playing players out of their natural positions is hard to win, especially the offence, Centre/PF is lack of JR, so they would be shut down easily; whereas SG and SF might not be strong at IS, so they might rely on long range shots.
No luck so far. However, I would try to swap one position (put SG into PF position) and see whether I can find some lucks next time.
It's difficult to win the game against strong teams.