Without the GK training for sure you need more time as you must do separate training for each player depending from position and % of his skills.
About greens, it's not much difference if you know how to train.
This guide is useful as that thread about fast trainers but you must read carefully .
If you want to train 22-23 y.o. players or without knowing if they are fast trainers, of course you 'll loose greens.