The choice would lie with the client. Factors would be:
Which lord had the deepest links with the client’s kin group.
Which lord was likely to be most use to them in the future.
Which lord they liked best.
The first was the most important.
All of the clients owned a share of kin group land to begin with and could bargain with a range of lords for access to more. If a member of the kin group died childless his land share was reallocated within the kin. That meant that an extra land contract didn’t necessarily trump an extra livestock contract.