Bava Batra 42: When Can Joint Owners Establish a Chazakah?

Consecutive use in place of ownership can establish a chazakah. Which suggests that a sale of the property to another party might actually build on the presumption of ownership, rather than cutting it off. Also, a new mishnah that lists those who have access to one's property, and therefore cannot establish a chazakah on that property - for example, a craftsperson, a spouse, a sharecropper, and a partner (in ownership). Plus, what does it mean to have a partner in ownership? It seems that there's a widely accepted dispute regarding how property would be divided - with all following ramifications regarding chazakah.