By putting Gengar at the first slot, there is higher possibility that Gengar could fire at most 2 ShB at Mewtwo. If it is put in the middle slots, it’s possible that it will get OHKO by Mewtwo charge move without doing any damage to Mewtwo at all.
Doesn’t the lag at start make it where he may be knocked out in first slot almost before you even load? When you can’t use the no team trick, of course.
I just put in 6 TTars and don’t worry about it.
Gengar is always at high risk especially if you are using only one
I put 2 Gengar at the first 2 slots against Mewtwo, the 1st one managed to fire two Shadow Ball, the 2nd one did not fire one and was hit by Mewtwo’s charge move, bad timing.
Quite a few factors could influence that and at the end of a day its all about luck