I've been in similar position (quantity Eggs Benedict under pressure), in
fact I was pressed into service unexpectedly for the sauce, which worked
fine because I knew this method. Someone else cooked the eggs for assembly.
Here are tips on both. (If possible, avoid commercial Hollandaises, they
have no soul.)

Practice these methods in advance and they will be reliable.

Make the Hollandaise in a blender, not too much at once. Have ingredients
and blender at room temp. (important!), the butter hot and melted. Blend
the egg yolks, lemon juice, and any other seasonings (few grains cayenne
doesn't hurt) at a moderate spin, then add the butter slowly, and continue
blending a few seconds until smooth. The hot butter partly cooks the yolks
(unless they happen to be cold).

For the "poached" eggs in the Benedict, _bake_ them in a nonstick (or
buttered) muffin tin. This makes them in quantity, they come out uniform,
not wet, and similar to poached.

Good luck! -- Max