First, go into your sound options and disable the SACU voices if you don't want to hear the SACU.
Second, redo all your tests because Percivals are much stronger than Nomads SACU mass for mass and for buildtime. Only when you heavily micro your SACU and use capacitor can they compete against Percivals. With no micro, Percivals will win all the time.
And Nomads SACU are not like other SACU, because they are more specialized. You didn't even notice that if Nomads SACU have no engineer arm, they are like normal units (they even leave wrecks): they can't build anything and take forever to get a new upgrade (they need to be assisted). Only with an engineer arm they can build PD super fast, and then they are not very strong with just one weapon. They still can reclaim, same as Harbingers which cost a lot less and Harbingers can reclaim and shoot at the same time, Nomads SACU cannot.
Also, maybe you didn't notice, but Nomads SACU are intended to add variety to their t3 game, with several types of SACU to fill different roles. Instead of having fast bot, super heavy bot, missile tank like UEF, they have only one tank, but a Rocket SACU, possibility of having a fast SACU, and heavy SACU, and even and Anti-naval SACU to make up for lack of naval units at t2 and t3.
Last thing, you cannot spam SACU as easily as Percivals, you will still need Nova, otherwise you will not be able to repel any t3 army with SACU only, it's just impossible.
NB: the kamikaze possibility with Resource Generator is there for more than a year. It's a secondary use for the resource generator, along with energy production and capacitor charge time reduction.