Yes, his S/T is not the same as Tobirama's. However, it's just too much of a coincidence for that to be named FTG Slash. There's obviously a connection.
FTG has different levels. And also, there is a difference between the effectiveness. But, FTG was also used by Tobirama.
Definatly a relation, I think Minato just made his a little different to become his own jutsu.
There is a technique that starts with the same name as a gentle style technique likeYou must be registered for see linkscalledYou must be registered for see links, but like you can see we're talking about 2different jutsus. They are not even related