It's probably 6 of one and half-dozen of the other. I've done it both ways and eitherway is basically seamless.
Most of our points have a June UY month but we have one contract, purchased resale, that has an August UY month, and we've used both methods at various times.
Personally I think the transfer is the easier of the two. That way ALL points can be used if desired. When linking, it's easy to have a few left over points in one of the contracts that can't be used and would need to be banked. For example one contract has 50 points remaining and a reservation requires 22 pts/night. That contract could be used to reserve 2 nights, but would leave 6-points remaining unused.
In your case, since the points might not split evenly because of an odd number of days, or because some days are weekend days and use more points, I'd suggest calculating the total number of points required for the reservation, divide it into two, and have one person transfer that number of points to the other who can then make the reservation.