There was no practice of "strengthening the senju gene pool". The only Uzumaki to have been confirmed to marry a Senju was Mito. Trying to claim otherwise is arguing from ignorance, and pure speculation at best.
Shame, you seem to be a smart fello, IDEOLGIES 'ONLY' indeed. WOW, only difference is one part of the younger son's bloodline kept the senju name while the other ones kept another. What are they if no senju, this assness has to die, really.