I'd guess that yes it will be half'ish because if SP gain is predominately rate and condition - since rate is fixed and condition is halved (on average)...... But we'd need to record loads of matches because there would still be the usual variation applied to 'training' and I don't think I have the appetite for that.
Just from the 2 friendly games I played - both sides hosting 1.
On the one team that doesn't buy players but instead signs Academy youths (too many teams to manage them all) in the friendly the fast trainers recorded 72, 67, 69, 68, 77 (condition burn was 13, 13, 9, 12, 9) which was more consistent than i expected. The fastest trainer got 77 using only 9 condition.
On the other team I've no idea who is fast or slow training because I manage them purely on performance and buy sell regularly - but 6 players gained between 60-75.