Have you looked at their ingredients? If they don't have fish oils (I'm guessing they don't) then yes you'll need some fish oil (in from actual fish) in your diet
Fish oil is completely different than vitamins. Its important to have the right amount of omegas in your diet, so if you arent getting it from fish you should supplement
Most of us are not eating enough omega 3's in our diet and way too many omega 6's. For this reason, I always recommend supplementing with a fish oil or krill oil supplement.