I have a MacBook Pro 16" (Late 2019) which has four Thunderbolt 3 ports, all of which support USB-C (both use the same connector shape). Currently I have it connected as:

1 - Thunderbolt to DisplayPort: Dell U2717D monitor
2 - Thunderbolt to DisplayPort: Dell U2415 monitor
3 - Thunderbolt to USB-C: Power Adapter
4 - Thunderbolt to USB-C/USB-A adapter: Dell U2717D USB bus

Dell U2717D bus has:

1 - Hard Drive Dock (USB 3.0)
2 - Glorious Mouse adapter
3 - USB to Lightning for iOS devices
4 - Drobo 5C (USB 3.0 Type C)

The way it's setup hard drives to each other and to MBP is kind of slow. Even connected with USB-A cables both the HDD and Drobo are twice as fast if connected directly to MBP.

The monitors support DisplayPort 1.2 MST (multi-stream transport) which means you can daisy chain them together. But turns out macOS does not support MST so you do have to connect each monitor separately.

I'd like to have the HDD and Drobo connected faster. Currently it's not exactly slow (I can watch videos from my Drobo fine) but file transfers do take longer than I expect. But even if I use USB 3.0 cables the bottleneck is MBP since the computer handles copying and the Dells support max 5 Gbps.