So we know that players gain speed when they lose weight
But do players gain strength if they gain weight ?
i.e. FB changed to a G

No but they should.

In Madden you used to develope players base stats by modest amounts year over year based on position. DTs would get strength.

It is like the essence of professional training. I understand that type of Thing might be a leap for a weekend project due to all the invariable effects.