Slotting Follow Up with multiple damage procs?

I was thinking it would be a pretty good idea to slot follow up with 3 damage procs or so, but according to mids the damage is much lower after the first proc. Should I bother onliy slotting it with one damage proc now...?

The damage shouldn't be lower as you add procs. Each non-purple proc is going to add an average of 14.4 damage to Follow Up (72 damage with a 20% procedural). Follow Up only does 33.4 damage at 50, so each damage proc is the equivalent of adding 43% enhanced damage to the skill.

Franken-slotting multi aspect IOs/HOs in the first three slots with three damage procs in the remaining slots is not such a bad idea, unless you want to hit a specific attack chain to stack the damage buff (which isn't as important for Claws Brutes versus Claws Scrappers).