MBR vs GPT Compatibility issue for creating Recovery Drive

Hello All,

My Cousin brother has 2 PC with the same Windows 10 Pro 1909, but different CPU and Motherboards.
His question is whether a recovery drive made in the first PC will be compatible for the second as well?

The actual situation is as follows:

  1. After installing a new MBR SSD drive, he cloned the Windows 10 Pro OS from his current HDD to the new SSD.
  2. The SSD functions 100% OK, but he cannot create a recovery drive, as the reagent service/environment is disabled.
    3 Following an instruction found in Google/youtube, he went to his PC>Manage>Storage>Disk management.
  3. Tried Change drive letter>add>Assign the following drive letter, but the last one is greyed, so he could not proceed in the process of enabling the reagent environment.
    he presumes that the a.m. inability occurs as there is no separate System partition in the C: drive.

BTW did he make a major mistake, by setting the new SSD as MBR and not GPT?

Is there any solution to this situation, apart from a new clean install, to create the Recovery drive?
Thank you.