The "secret" - difference - is:
1v1 Guards:
You training
JS, HD, DR
1v1 Fowards:
You training
JS, HD, DR, IS
The first difference is Fowards train 1 more skill.
The second is:
On 1v1 Guards, lower players have more effects - here, in my opinion, less than 6'6".
On 1v1 Fowards, high players have more effect - more than 6'6".
Here you mean "more effects" like speed of training.
This is the great difference of one to other.
On Jump Shot training, however, don't have anything vantage on speed if you train to Guards or Fowards.
My opinion.