Hi, please find my suggestions below:
It can provide them with more experience and progress in their current jobs since one can promotestep by step(I prefer the word "gradually") in the job and being expert in that field.
Who do "them" and "their" refer to? the first part of the sentence has no subject to refer to.
has its own merits.
---> you used the exact phrase at the beginning of the body paragraphs. Avoid any types of repetition.
for achieving (use synonym, such as "gain", "obtain", etc. ) new skills
I believe that doing the same job may kill the motivation of people for working efficiently.Hence , I personally prefer to experience different occupations not only for learning various skills but also for having the opportunity to have relations with more colleagues and managers
--> I think if you delete the first sentence, you can express your opinion more clearly.
Hope this helps,
Cheers,
Ahmad