on isolation exercises

They're good. They work. And they have their place.

But...

Isolation is one of those weird topics its easy to get passionate over. Ask yourself this - do you want a bigger body oe bigger (body part)? If you have the time and the capacity and the passion then go for it. Conversely if your entire body is weak and small, reconsider. It isn't that Isolation has no value, but it has less value in this instance. Isolation brings up weak points. But when your entire body is a weak point your training capital is best spent elsewhere. 

I.e. worry about small arms or shoulders when your big compound lifts are respectable or stalled out.