In the Polish tech tree, the medium tanks CS-59 and CS-63 both have a radio called R-123 with the same specs.
[![Tech tree: CS-59][1]][1]
[![Tech tree: CS-63][2]][2]

Why can't I use the radio R-123 from the C-63 on the CS-59?

I cannot find any related information via Google. Also, I didn't hear anything about this in youtube videos about those two tanks that I watched so far.



  [1]: https://i.sstatic.net/AcIZh.jpg
  [2]: https://i.sstatic.net/ZEgmK.jpg