Adding a Second Yeast strain to a fermenting beer??

So I have this Dreadnought Clone fermenting with an English ale yeast. I pitched it about 2 weeks ago. I dry hopped it with a a good amount of columbus and whatever else i felt like throwing in there from the fridge...(all in all 3.5oz).
I don't plan on moving it off the yeast cake (English Ale WL) and I was wondering if i could pitch some California Ale WL yeast on it after the English falls out of suspension? What would it do? Would it remove the dry hopping aromas if fermentation were to pick up again?

If the fermentation is finished, adding more yeast is just a waste. You are dropping your new yeast into an environment that is void of fuel and oxygen.

P.S. Yes. Adding dry hops during active fermentation is not a great idea as the volatile aroma compounds are driven off by CO2 off gassing.