That's just Thanos off his throne in the center, Corvus Glaive and Proxima Midnight on his right, Ebony Maw and Cull Obsidian (Black Dwarf having gotten a clever rename because I guess that's not a name you can take seriously in a live-action context) on his left.

(No Supergiant makes sense. If you're gonna drop a member of the Order to keep the cast trim, it's better the one that doesn't really have any moments you can adapt in the MCU.

I wonder if the remit for the Order's original creation was just " give us things we can use in the movies " - we're apparently getting Strange vs. Ebony Maw, after all..)