If I were to follow the 3,000,000 number for base Goku, my numbers would be something like this:
Kuririn : 200,000
Gohan : 800,000
Piccolo : 1,500,000
Gohan enraged + Masenko : 1,800,000
Freeza (3rd form) : 1,900,000
Vegeta (post Zenkai) : 2,400,000
Freeza final form (speed) : 2,500,000
~ power : 3,100,000
~ speed up : 3,100,000
Besides everyone being too tight together, Piccolo post Gohan and Kuririn's powers would be a beast, considering both handed to Piccolo almost all of their power.
Piccolo ('powered up') ~ 2,500,000
That'd make him stronger than Vegeta, which doesn't seem to work very well. Vegeta should still be the strongest when they were teleported back to Earth.
We could assume Gohan lost a lot of power post his full power blast against Piccolo (was that a Masenko?)... but Gohan doesn't look so screwed up after the blast... all that is shown is him a bit out of breath, to which he quickly recovers right after. Besides, if he lost that much of his power, I think a statement reflecting that would be made... Gohan doesn't say he spent a lot of energy or anything like this.