It's a common problem for old Macintosh archives. A lot of the stuff that was archived as "warez", back when the stuff was new, was intended that Mac users would download everything directly to their machines. Of course, that is almost impossible today.
So instead of standard 400k, 800k, 1.44mb, or ISO images, you get all kinds of crazy compressed formats like SIT, SMI, HQX, BIN, or such. Worse yet, archives that have been converted to ZIP/RAR/7z but automatically discarding resource forks, that renders most contents unusable.
So, unfortunately, the workflow for getting most Mac archives to a real Mac involves loading them up in an emulator, extracting them, and making disk images.
If it is something you do a lot, some Macs can support other options such as networked Apple file sharing, or SCSI Iomega Zip drives.
Actually, Basillisk II has a really neat feature where you can pull a SCSI hard drive from a Mac, and attach it to a PC with a SCSI card like an Adaptec AHA-2940U and then mount it directly within the emulator. Makes an easy way to install MacOS or transfer over very large archives.