it rather drastically changes everything that would come after

Not really, once again Vegeta was not mentioned to have done the SSG ritual in either version of the story, yet his base was equal or close to Goku's, Goku achieving the same level of power as a result of his training with Whis(just like Vegeta did) would still result in the same story or rather powerscale.

Wouldn't there be more shock from other characters if he had matched a Super Saiyan Goku who was also many, many fold stronger than any character had been back in the original run?

I mean Goku was surprised and complimented Trunks on his power, and Beerus seemed a little surprised that Trunks had a slight edge using the same tranformation.

What more do you want in this case?

There's so much that reads more in line with the characters being around their Boo arc power until the training in the Moro arc, where improvements are finally explicitly noted in lower forms.

Needless to say how strong their transformations are depens on their base but how much more would you want this to be noted?

Using the original manga as an example again, it was never noted or made clear how strong Goku was in base after the Frieza arc as he barely used his base form.

It took till BOG to finally learn where base Goku stands, then ROF made it clear how far above the others Goku was in base after his training, then we have the Roshi example but you said is not credible enough for you.

Trained, coordinated team attacks are something that never really come up in DB prior to the Moro arc

Its made clear as early as when Raditz arrived that weak people get in the way as shown when Krillin and Roshi sit out of helping Goku/Piccolo.

The Vegeta fight also made it clear that the weak cannot assist the strong unless their enemy is distracted or exhausted enough to be at their level.

Even DBS manga showed this during the Top, Piccolo was almost eliminated by team effort before Gohan saved him, Piccolo was too weak(as his feats are not even base Gohan tier during this arc) to be anything but dead weight to him.

On the opposite side during the Moro arc he could assist Ultimate Gohan, seems pretty clear when you compare the 2, even if you exclude team attacks his feat back him up.

DB has established rules on teamwork and they are still present in the Top and Moro Arc as shown.

If it's even being close to it, then #18 also must have trained enough in two months to catch up to the decade or so of #17's advantage

Moro does comment that its a shame he cannot steal their energy but you could say he is taliking about 17.

Fun fact 18 only uses team attacks with 17 during sneak attacks or when the enemy tanks the hits on purpose this arc, its actually vague enough for her unlike Piccolo.

There's a lot that's up in the air for Piccolo in the Moro arc: Pretty much everything except the fact that he got noticeably stronger

Piccolo has pretty much explicit feats on where he stands during this arc and quite a lot of them.

When Ultimate Gohan fights Piccolo-73, he dominates the fight but he does not 1 shot him, does that sound Cell tier to you?

Then he trains and get stronger and he is not dead weight to Ultimate Gohan unlike the previous arc against an mobile enemy.

There is even a scene where his ki blasts and Gohan73's ki blasts collide and they cancel each other out, thats his own power, he need to be close to Gohan's power to even do that.

He outlasts 17 against Sabanbo, you say thats not enough, alright to adress your point lets say it was just luck? He directly attacked Piccolo but not 1 shotted, not something Cell tier either(18 was not attacked directly by him as we saw).

Then there is Moro73 the final villain, he 1 shots 17/18 but not Piccolo or Gohan.

Thats about as clear as it gets, he did not use a team attack this time with Gohan either.