It's also a possibility that they're part of the various PMCs: Wagner Group, Redut, Convoy, Patriot, Yastreb, Rusich, Tsarist Wolves, or the Russian Imperial Movement
That have been sighted or associated with activities in Ukraine - as national volunteers are getting (relatively) fancy signing up bonuses, it wouldn't surprise me if some outside of Russia see it as an opportunity.
Difference is a fully virtualized Linux VM running natively, compared to termux terminal emulator running in user space with an independent package manager.
So you (in theory) have more hw access, access controls and aren't limited to Android user space running a single user emulation - with no privilege separation existing within termux.