If E does indeed reduce T on its own, there would be no reason to add an anti-androgen such as Spiro. But, unless you are taking E in the form of pellets or intramuscular injections (which I doubt) or your T levels are already quite low, I don't think it will be enough. In any case, it's a change in the right direction and that way, at least, you'll know, if you have side-effects (which is unlikely but still...), what is causing it.