help installing windows 10 on late-2012 iMac with 1.12TB Fusion Drive

Stuck trying to install windows 10 on my late 2012, 27" iMac with a 1.12TB Fusion Drive: any help would be appreciated.

Brief background: Re-inherited this old iMac back after passing to a family member to use, and decided to turn it into a windows machine. (because I refuse to let a company that's skimping out including a charging brick because of "the environment" trying to plan-obsolete a perfectly fine computer). Struggled to re-install OSX, then thought maybe just wipe computer and install only Windows. Seemed too complicated so thought I'd do the "simple" thing (lol) and just dual install Windows and keep the OSX partition as small as possible.

Basically stuck before I can even get started at the "your disk could not be partitioned" phase, after doing all the "correct" steps going through Bootcamp, and all the "correct" trouble shooting of running disk utility to repair drive etc.

Been reading through lots of previous posts, especially lots of Loner T replies, and it seems that there's a lot of variability with these Fusion Drive iMacs, so trying to figure out what I can actually do.

To get to the point:

• late 2012 iMac, 1.12 TB Fusion drive.
• on Mojave 10.14.6
• even downloaded a 1809v2 x64 version .iso of Windows 10. (only official version from Microsoft now online is a 22H2 fusion international version)
• creating the 16gb USB with Bootcamp tool seems to work fine
• can get to the slider portion of deciding how much of drive to allocate for Windows partition
• click partition and get the "disk could not be partitioned" error.
• disk utility repair find no errors
• even tried command line fsck stuff through recovery and no errors

diskutility list thing shows this:

/dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *121.3 GB   disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:                 Apple_APFS Container disk2         121.1 GB   disk0s2

/dev/disk1 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *1.0 TB     disk1

   1:                        EFI EFI                     209.7 MB   disk1s1

   2:                 Apple_APFS Container disk2         1000.0 GB  disk1s2

/dev/disk2 (synthesized):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      APFS Container Scheme -                      +1.1 TB     disk2

                                 Physical Stores disk0s2, disk1s2

   1:                APFS Volume Macintosh HD            35.4 GB    disk2s1

   2:                APFS Volume Preboot                 24.1 MB    disk2s2

   3:                APFS Volume Recovery                507.6 MB   disk2s3

   4:                APFS Volume VM                      2.1 GB     disk2s4

If anyone can give guidance about what I can do next, would be greatly appreciated.

Not gonna use computer for much, so happy to just keep OSX and load a Windows partition.

Also happy to just completely wipe drive and install Windows only if that's easier.

Also not attached to Mojave, so if Catalina easier happy to do that.

Thanks in advance.