I get over 1M for every friendly at level 17.

I usually do training over friendlies because you can control their final condition easier, but I'll play friendlies sometimes if I need packs. Also, if you pick the wrong opponent, you'll get lots of injuries, sometimes less packs. You're only guaranteed the green pack for making a substitution. I'd pick a lower level manager with an attacking formation.

Do you get better skill progress from friendlies or training? Like progress per point of condition.