I do have a USB drive with a Windows 10 installer but it's not mine and it is not to be modified, so that doesn't help here.
The above is only really any good if it has the latest ISO on it which is version 1909, you will find yourself having to install any missing major and cumulative updates otherwise and that could take you a few hrs atop of the Windows and driver updates.
You could save your drivers to one of the data only drives and reinstall them when you put the drives back online after clean installing Windows.
The firmware can be updated after the Windows and/or as part of the drivers installation, just remember to create regular restore points along the way.
The small partitions to which you refer, when Windows 10 is installed Windows creates it own three partitions as part of the process, just like the OEM recovery partitions you have duplicates of the originals, below is how Speccy reports a typical Windows 10 installation on a storage device;
Partition 0
Partition ID: Disk #0, Partition #0
File System: NTFS
Volume Serial Number: 7878DDDD
Size: 528 MB
Used Space: 421 MB (79%)
Free Space: 107 MB (21%)
Partition 1
Partition ID: Disk #0, Partition #1
File System: FAT32
Volume Serial Number: 4A79C891
Size: 96 MB
Used Space: 26.2 MB (27%)
Free Space: 69 MB (73%)
Partition 2
Partition ID: Disk #0, Partition #2
Disk Letter: C:
File System: NTFS
Volume Serial Number: BA84FB8C
Size: 465 GB
Used Space: 93 GB (20%)
Free Space: 371 GB (80%)