Number of Exercises per Body Part?

Hi there, I know this is a bit of a general question, but primarily for lean mass gain do you think doing two exercises per body part is enough? I usually hit each area twice a week. For example

Chest, - Bench & Flys
Back, - Lat Pull down, seated cable row (and some lame attempts at chins)
Legs, - Squat, split squat, DL

Most are 3x8 except squats, bench, DL 5x5 as these are mostly 90% as trying to gain strength on these in particular at the moment.

Oh and also, trying to keep the workout times to a minimum (in order to fit in cardio too!), would you consider it necessary to still do isolation work on the arms, sometimes after chest day they are really sore for a couple days, and also on back days they get hit too.

Thanks very much

My coach has had me do very lil isolation for arms, I get tricep pull downs but alot of my others are compound movements to hit biceps and triceps.

Also 6 days a week seems like a lot (from your other MWA post)

[quote]meechel wrote:
My coach has had me do very lil isolation for arms, I get tricep pull downs but alot of my others are compound movements to hit biceps and triceps.

Also 6 days a week seems like a lot (from your other MWA post)[/quote]

Yeah 6 days does seem a lot doesnt it, but im working a split which is chest/back/legs and trying for twice a week, how do you do your splits?