I would at least attempt talking to the tank first. Tell the tank you're good with them pulling more, that you can keep them up easy. If they still refuse to pull more, and the dps ALSO want to do bigger pulls, and you can keep everyone up then I guess go for it. (If the dps also prefer smaller pulls and you're outvoted then I guess just deal with it.)

It's kinda rude however to just start pulling for the tank with no attempt to communicate first.