Fusion multiplier's inconsistency

[p-hyvo]

Let's get started :
The first time metamorian fusion was introduced, Goku strongly implied that, in his opinion, gotenks would have been enough to beat buu (obviously, with ssj) and the fusion was sold as an incredible technique (who it is). In the first coming, is pretty clear than base gotenks > ssj goten + ssj trunks, basing on piccolo's and everyone's reaction to him. Goku , in his ssj3 wasn't at his full power, because using all of ssj3's strength would cost him all his time on earth.
So, let's say
Goten = 0,95 , ssj = 47,5
Trunks = 1,05 , ssj = 52,5
Gotenks (Bfp)x8 = 380 , ssj = 19'000
Goku 80 , ssj3 (50%) = 16'000
Fat buu =15'000
After the short ROSAT training, piccolo didn't notice any substantial power up from both goten and trunks, but he thought that gotenks had gotten a lot stronger, so stronger he initially thought that base gotenks could beat buu , and even trunks and goten themselves believes (having the strength of the original fat buu in mind) that base gotenks could compete with him, making effectively base gotenks (post ROAST) at least 30 to 40 times stronger than his first coming
Goten = 1,035 , ssj = 51,75
Trunks = 1,085 , ssj = 54,25
Goten+trunks = 106
Gotenks (Bfp) x300 = 15'125

That concludes the z segment. In gt and super, fusion has other 2 completely diffemultipliers :
In gt, following the gt perfect files, the result of the fusion is dozens of times stronger than the parts, so it is 24x/192x the weaker part ( as we know, the weaker one is who counts, because the stronger one,has to power his power to match the weaker) .
By itself , that's anyway an huge multiplier, considering that in gt ssj is 2x base form , the 24x/192x multiplier would be the same as a 600x/4'800x multiplier in z.

In dbs , metamorian fusion seems to just be >strongest form in common for the parts, basing on dbs broly where base Gogeta seems to bee in the,same tier of ssb Goku, or even a bit stronger.
Usually, use that logic :

Goku = 1
Ssb = 30'000
Base Gogeta = 40'000

And that's another completely different multiplier.
What do you think? Why fusion is so inconsistent? Imo is just a writing fallacy, or easier fusion just has a plot multiplier and there's not fixed multiplier, making it depending on the situation

[theherodjl]

Fusion, like any other major power boost in DB, has no set multiplier. It all depends on how much Ki the user currently has, how much potential that can be drawn out from within, and how well it clicks together with another user's Ki. Note that Kibitoshin was relatively weak for a fusion because the individual Ki of Kaioshin & Kibito was too low to make any sort of difference against even Boo's weakest forms and because Kaioshin & Kibito lacked the potent chemistry of Saiyans.
If every power-up was set in DB then we wouldn't have a long list of moments where characters in weaker forms suddenly pulled ahead to match opponents that they previously couldn't beat with more powerful forms(most especially the mindfuck that is Super Dragonball Heroes ).

[Grimlock]

If every power-up was set in DB then we wouldn't have a long list of moments where characters in weaker forms suddenly pulled ahead to match opponents that they previously couldn't beat with more powerful forms(most especially the mindfuck that is Super Dragonball Heroes ).

Care to provide some examples?

[Hugo Boss]

After the short ROSAT training, piccolo didn't notice any substantial power up from both goten and trunks, but he thought that gotenks had gotten a lot stronger

If Goten and Trunks are (let’s say) 30 and 35, their fusion will be 1,050. If they have small gains like being at 35 and 40 respectively, their fusion would result in 1,400. So, while they separately get small gains, their fusion becomes much more powerful. “Dozens of times” is not literal.

[ahill1]

The main problem imo lies on Goten and Trunks' apparently small gains in the RoSaT in contrast with base Gotenks elevating Piccolo's hope who formerly thought it'd take a miracle for them to compete with Super Boo. That leads me to believe that the being Gotenks improved on his own and that there Goten and Trunks completely mastered the fusion, benefiting entirely from its power boost.

[ankokudaishogun]

"Fusion" is a technique unlike Potara.
Gotenks was much stronger because Goten and Trunks improved their master of the technique, resulting in a bigger multiplier