But if two bases theory is true, why didn't Goku just turn on that God power instead of going Super Saiyan, since that would be much higher? I mean, with SSB at least they said it drains stamina (wtf Super?), but there is nothing pointing to it.
Let me explain how I think this works:
Goku has both God ki and normal ki in his body. He is stronger than when he was in BoG, but at the tail end of the God scale (1, compared to Beerus' 10 - which reflects the tree comparison Whis did a while ago). This would put him at a Buuhan/Vegetto level of power (stronger than SSJ3, but not by much compared to the gods). Then his Super Saiyan form multiplies his normal ki, that is no longer the main source of his power, which puts him at a 5 on the God scale (I am going with my own theory here, that the scale works like tiers, not actual numbers, and you have to be 10x more powerful to jump a tier, so 50x 1 - tier 5). Then his Super Saiyan Blue multiplies his God ki, to a point where he can no longer be sensed (since you can have God ki and still be sensed, like Dende) and puts him at a 7/8 on the god scale. He can't just multiply his God ki by himself, without a transformation... that never worked. Maybe with a Kaioken? Combine that with the fact nobody comments anything in either RoF or the tournament, not even Goku himself, that he is using a different "base" form.
Now, let's go back to the RoF arc. I used to think Gohan's Super Saiyan form was used to unlock his full power he had in his ultimate form, but due to recent events I have retracted that and I think he regressed to his Cell Games level (the earliest point he had SSJ, there's no way he's getting weaker than that). That is enough for him to be stronger than Piccolo, if we also assume that Piccolo stayed at around that same level. However, after RoF, Piccolo and Gohan start training again and based on Gohan's hair (I know, strong freaking argument

) Gohan achieved his Ultimate powers back. Piccolo was still dominating that sparring, so he finally managed to get a boost in his powers, since he finally had a powerful partner (we know from the Cell saga training together with someone is better than by yourself), so Piccolo is now at SSJ3 levels (close to base Goku in the U6 arc). Golden Freeza would be like a 7.5 - 8 on the scale, while his 4th Form would be around an 1, maybe 0,5.
Frost's Final Form is stronger than a 1, therefore stronger than Piccolo, but nowhere near the 5 SSJ Goku would be. I would say a 3 at best, but after getting a beating from Goku, he falls back 1,5, stronger than Piccolo, but not so much that the green man can't win if he fights smart (like he did in the anime), but there's no way he could if he doesn't, like in the manga (remeber, 0,5 on this scale is 5x, and in the Saiyan Saga the Makankosappo was about 3x higher than Piccolo's base. With a little more charging it can surpass Frost).
The only problematic one from here on out would be Magetta, since he was giving a hell of a hard time to Vegeta, but I guess you can put that on the fact that Vegeta was only in his Super Saiyan form, which wouldn't be as durable as Super Saiyan Blue, and therefore could still be hurt by magma. Combine that with the fact he was probably not fighting at his best, being constrained by the barrier and exhausted due to the heat and I guess it makes sense.
Cabba then being Super Saiyan 3 tier in his base is not so unbelievable anymore, since he is not in the league of the gods. And not even his Super Saiyan form woud be either, since it was weaker than a tired Super Saiyan Vegeta. I guess a 2 on the scale is enough for him.
Botamo is a non-factor since he surely is not even in the SSJ3 league, since Goku was toying with the guy and had 0 problems against him even with his ability (and not just due to tournament rules).
Then the only problem left is Hit fighting Vegeta in Super Saiyan Blue, but Goku in base. Well, Hit is an assassin and we know for a fact he is only targeting the vital points. Vegeta didn't know of Hit's special ability so he was at a disadvantage from the start, compared to Goku who knew from the beginning what he should look for. Also, the only explanation needed for that is that Hit is suppressing his power and since we know he can do that, Goku's 1 base form was able to hurt Hit, because Hit was not fighting at a 7 level power, but only at a 1. Next episode should shed more light on the matter.
If this is true, then Buu would still be stronger than Botamo, Cabbe, would have no problem against Magetta and be strong enough to put up with Frost in even his Assault Form and due to his abilities could have stalemated at least even Final Form Frost, explaining why he was such a loss for the team. (How cool his fights could have been...)
This works well without the need of two base theory. The only thing it discredits is the scale, but not entirely, since I've correlated it with the tree comparison, which was stated regarding Goku and Vegeta's base forms, since in the same conversation (I think?) the Oracle Fish says that they could just turn Super Saiyan. If it contradicts anything but the Toriyama numbers, please feel free to point out any holes, but I really don't think it does, especially since I don't think Toriyama ever intended for them to be used as literal numbers that you can calculate and say how strong one must have to become to surpass the other, but more akin to what I suggest, literal numbers to imply huge differences between the two. And since the 50x = 5 works so well (God Goku was a 6, then his power dropped to a 5 in Super Saiyan), I went with one tier = 10x.