I think the best you can is remove the Glow plugs and crank the Engine over. That will quickly fill up the Oil Galleries and Oil Filter housing with Oil before you start. Without putting much load on the bearings.
Make sure the Shutoff is activated; no need to squirt raw Fuel into the Cylinder.

Also common practice is to already have used assembly lube on the Bearings when you assembled the other Engine parts.

It would not hurt if you poured some Oil over the Camshaft/Rocker Arms. But, assembly lube could be used instead.

I have never experienced or read of any one packing an Oil Pump with Grease, but I have read of People using Grease as an assembly Lube and it blocked Oil Passages and cause Oil starvation in some Bearing.

If you like you could mix something like 50% Engine Oil and STP and coat the parts in the Oil Pump with that. We used to use that as an assembly lube in Turbo Chargers on the Bearings and journals. It does not block any Oil passages.

What does the Mercedes Service Manual have to say?

This is just thinking off the top of My head but if you poured the Oil into the Oil Filter Housing without the Oil Filter some of that Oil is going to go towards the Oil pump and some is going to draing towards the bearings and if the Oil filter on your Engine has that stem like the 617.952s do some of the Oil will drain back to the Oil Pan through the Hole at the bottom of the Filter Housing where the Stem goes.
What I am saying is dump the whole amount of the Engines Oil in through the Oil Filter; shove the Oil Filer in and as soon as you can to put the Oil Filter Cap on and seal it up Cranke the Engine with the Glow Plugs removed and the IP shutoff activeted.

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84 300D, 82 Volvo 244Gl Diesel