All of that is present in both the anime and manga. If they're shown to be much stronger than SSJ3 Gotenks in the anime and they had certain fights play out in certain ways during the tournament and then in the manga they have the exact same results as in the anime....then why are they at regular levels in the manga?
This is a really bad argument since the two base theory would allow us to explain everything weird about power levels in the Super anime, which in science and logic we call this a good thing. It's a good thing if a theory solves problems.
I can't believe I have to defend this from both sides.. In the anime we are shown the Copy Vegeta saga and various other supporting items. These support the base "normal" as being above SSJ3 level. However in the promotional manga continuity, these events are not shown. Furthermore in the manga, Goku is not shown to fight anyone in his base which has been independently confirmed to be "God" level. In fact its arguable that Hit is weaker than a SSB in the manga while 10x stronger than SSB in the anime. We already have different forms, and different interpretations of those forms, so why not different power levels?
In the manga SSB weakens substantially after multiple uses due to Ki drain.
In the anime SSB can be strengtned with Kaioken due to perfect Ki control...
In the anime SSG is a one time form.
In the manga SSG can be used at will.
In the anime, SSB is shown to be the successor to SSJ in terms of power levels
In the manga, SSG is shown to be above the SSJ levels in terms of power.
In the anime, SSJ Goku post Beerus is equal, if not greater than SSG at this point.
In the manga, SSJ Goku post Beerus is still below SSG.
My point stands. You cannot say what is true for one media is true for the other, and as it stands now the manga and anime have two VERY different interpretations of the same story, the power levels, the forms, and what they can do. As such I believe two bases (God form non-SSJ) is true for the manga, but not true for the anime because that is what has been explicitly shown in both.