Goal of this game isn't to have real SF ;-) Goal of this game is to win ;-)
In 5th division good SF isn't needed. In 5th division quick development is needed and therefore 175cm for SF is the best height ;-)
You were in different situation because You received club in 3rd div. But realities in 5th div are different. Manager should promote to 3rd div. as soon as possible and then he will need better players than he can train himself alone. After promotion to 3rd he could think about real SF.
mmh i don't think so, if you had the oppurtunity to train a good SF prospect last division is ideal. Because you can use him off position, and he is still strong, so it is easier to combine succes and ideal training then in more advanced leagues. And it is the most difficult Training, but you don't need an Master to do it, so you could get the necessary knwoledge by reading quite fast too.
About the topic, SF height is pretty difficult to say - yeah probaldy 1.90-2.00m are ideal, but the difference in training time isn't that huge because you had to train stuff which is in favour for big player and for small players so that a better basic skill set is more important in my eyes and not optimal size in this cas eshould be considered then for the type of the SF.