Be sure to apportion the staff's contribution to all the partners, not just the one with positive income.
That is, if it's a 25% per man split, and the staff contribution is $10,000, the partner in the black only absorbs $2,500 of it. The other three will all have losses that are $2,500 greater each.
(I try to draft my document to exclude all HCEs from the SH. The company can make it up by making a profit sharing instead. Well, for all my New Comp plans, anyway.)