There are a number of optional dependencies which add support for other archive types:
$ pacman -Si ark
...
Optional Deps : p7zip: 7Z format support
unrar: RAR decompression support
unarchiver: RAR format support
lzop: LZO format support
lrzip: LRZ format support
...
No, - and that was the solution, thanks! Interesting that Ark doesn’t include p7zip by default given how usage for 7zip file formats has increased over time.
Thanks for the quick answer both of you! Much appreciated.