Are utilities -water, gas, electric - included? If so, 60/40 is a good split. If not, your 5/12 - 7/12 may work, but the utility costs need to be split in thirds. You are getting separate phone lines, aren’t you?
If they insist on 50/50 you get the bigger bedroom. And the extra closet.
Just wait until shopping and chores get thrown into the mix.