I once had a 150g with a queen trigger (much more agressive than pic or humu humu) and 2 perc clowns and they were fine.
also had a peppermint shrimp and he was okay
BUT BUT BUT..
had LOTS of rockwork and hiding places along with the longtip anenome to prtect the clowns.
BIG TIP is... (will they be okay?) possibally.. but will they be happy?
my suggestion is if you want to do that,
1. go to your LFS for your purchase and see how aggressive the trigger is. Ask to watch him eat and watch him for a while before and after eating.
2. I was at LFS the other day and they had a Picasso Trigger with a Maroon Clown and a Dogface Puffer... they were all happy and eating frozen shrimp from the guy's hand.
**** Check temperment**** easier done at lfs than an online purchase and not being sure how agressive your choice is.