fin cluster too long need sugestions

I have just finished installing FCS fusion fin plugs in my second board I have shaped and I realised my fin position is off. It is a 6'3" thruster, rear fin at 3.5" and side fins at 12" and 1" off  the rail. An 8.5" cluster which i gather from other posts is too long.  I have not glassed it yet.

I was thinking I could cut a 1/4" off of each fins mounting tabs and move them closer together to get it down to 8" which is better i think? Will it work? Any other suggestions?

Your fin setup seems pretty standard. Maybe a littlebit up by not drastically

just re mark the side ones at 11 1/2  toe em in 1/4" over 4.5" base.

2 cents