Wedding party attire

Hey guys I'm in need of some help! We decided a long time ago that our groomsmen would be wearing light grey suits to go along with my fiances charcoal suit. The bridesmaids are wearing dusty lavender dresses... I'm asking for help because my fiance was looking through the formalwear catalogue and came across this plaid suit and he loves it, but I don't think it would work with the boys light grey suits. I am all for him being able to have control of what he wants to wear to our wedding, but I'm thinking maybe we should switch the groomsmen to navy suits!

1) would navy go with both the grey plaid and the dusty lavender dresses?

2) our colours are purple, grey, and "succulent" so would introducing navy be a bad idea, or would it break up the colour theme a bit more and seem a little less extreme and in your face?

All the girls have different dresses, but they're all "dusty lavender" in sorella vita. This is the same dress and colour that one of my girls got, just for reference.

I think that navy suits could potentially go really well with the dress colour, but need some help! Shoot your thoughts and ideas at me please