Are they in the same bucket? If you don't have enough room fand the birds touch you can get a section that doesn't pick up much brining benefits, if so be sure to turn them several times during the process.
And good luck!
Are they in the same bucket if so I would swap them after a few hours and then again in a couple more hours. I alway brine turkeys by themselves cause the brine recipe is for one bird not two unless you have doubled the recipe for two birds.