FIND THE BOTTLENECK - Mac Studio, 10GBe, Cat 8, SSDs

Professional photographer/videographer, two people in studio looking to have a shared server to both archive and work off of in office and also remotely.

The setup:

Server brain: M2 Max Mac Studio, 32gb, 512SSD.

OWC external enclosures:

Two Express 4M2 units with Samsung SSDs in RAID5 setups. One is 4x2TB (6 total) and one is 4x4TB (12 total). Each directly connected to Mac studio via Thunderbolt 4.

Two OWC Thunderbay 8 8 bay HDD enclosures daisy chained and then connected to Mac Studio via Thunderbolt 3.

Mac Studio to a MokerLink 8 Port 10Gbps Etheret Switch via Cat 8 Ethernet

Cat 8 Ethernet from the switch to two M1 Macbook Pros (various specs, 32-64GB, Max to Pro) via an OWC 10GBe to Thunderbolt 4 adapter.

Silly drawing attached.

THE PROBLEM:

getting over 2000MB/s read/write on the 4M2 with SSDs on the host computer, but only 400-500MB/s when speed tested through the network (blackmagicdesign disk speed test).

I'm sharing the drives from the Mac Studio via MacOS's file sharing options. I don't know much about this other that I've turned everything "on," "logged in" on the target computers, and the remote/network drives pop up and are accessible, even if they're a lot slower than I feel like they should be.

Internet sharing also on; we have 2.5G fiber, but the router they gave us onlty has a 2.5G in but 1G out ethernet, so I'm only pulling 950+ on the internet connection... but I'm getting that through internet sharing through the switch to our target computers just fine.

Any ideas?

THAAAAAAANKS!