I think that is because the 7.62 TOK is too hot for some of the guns like the Broomhandle which are chambered in .30 mauser. I don't believe it is due to cartridge dimensions.
Not really. They are essentially the same round. There are some minor dimensional differences but all "official" sources show them to be completely interchangeable.
I shoot Romanian Tok ammo out of my broomhandle all the time. The velocities are the same as Prvi 30 Mauser, hence the mean pressure curve is the same. You can't get the same or lower velocities with a higher mean pressure curve. My 30 Mauser handloads are actually slightly faster.
Now, there have been some surplussed Tok ammo that is hotter than spec. Turns out, that was the reason it was surplussed. This is the legendary "subgun" ammo, which was never specifically manufactured for use in subguns, but was simply overloaded. So, the caveat is, if you shoot Tok ammo, make sure you know what it it. If it will destroy a C96, it will surely destroy a CZ52.
Always treat surplus ammo with respect. Understand the reason it was surplussed. Former Eastern Block countries are just as liable to surplus out of spec ammo as they are in spec ammo.