EV of medium pp vs 2 or 3 callers

I am a newbie, 30k hands or so party 1/2 and 2/4.

I ran into a situation where i need some advice. I had 2 fishy guys, over 50% vpip with no aggression. One was on my left and the other on my right. When the 1st fish limped in, i would raise medium pp (say 77-TT) to isolate. I think this is +EV vs his random limping hands. Yes?

The problem was the other fishy guy would cold call alot, with very random hands (eg K9o). Are my medium pp no longer +EV vs two random hands? I think this may be a poker stove question but I have never used/dont have it. the rest of the table would consistently fold and leave it 3 way. Any help?