The Phantom was a pump action and the Legend / Nemesis was semi-auto and so any similarities was at best, cosmetic.
However, it did emulate the single body valve system which the Phantom possessed.
I would think Tom Kaye's Automag was closer to the Phantom in its design but I'm not really sure if there was a deliberate design similarity that had the Nemesis copying the Phantom.
I'm afraid the Nemesis was a prime example of 'All show, no go'.