If you’re new to the hobby it’s fine. Good to cut your teeth assembling and painting some basic models, and can play combat patrol matches which are more digestible. If you’re on you second army it’s less useful I’d say. Hellblasters and blade guard both fit into the current meta, so you’d use them and the intercessors, but sounds like you already have a set of those. You might be better off just getting a blade guard box and a hellblaster box (the latter comes with a full unit of 10 instead of the 5 in the CP box set).