Is it valid for one contractor to serve two owners of a single orchard with specified fractional shares from each owner's portion?

Primary text

If an orchard belongs to two individuals, and one contractor is hired such that he receives half of the first owner's share and one-third of the second owner's share, the contract is valid, provided the contractor knows the exact share belonging to each owner. This is permissible because the single contract with two owners is treated as two distinct contracts, and the contractor could have stipulated these terms if contracted with each owner individually.