Goku vs. Hit fight and the lack of Tagoma in the RoF omake in the manga tells me base Goku is really fucking strong in the manga and so are the golden forms. You can just credit that to Whis' training rather than absorption of SSJG
I just like to think it isn't really stated, but you can infer it from feats like base/SSJ Goku's feats in later arcs of GT (giant turd).