I've had success with a similar build on one of my Thunderbolts, so I thought I'd try a variant of this on the Griffin. I find that long-range builds are a lot easier when I'm first mastering a mech. After I master this, I might switch out to more of a brawler build with SRMs.
I was playing with my Griffinpult build, tweaked it, and lo & behold I ended up with something very similar to yours:
4/5, I actually played with a build very similar to this the other day and it was quite fun watching people try and close on a missile boating Griffin only to discover the three Medium Lasers