The necessity of configuring the HR module when creating a new company code

My Client has many company codes in a single client.

New company codes are created whenever there is a new statutory entity creation.

Usually we would have employees in say CoCo 1000 or 1100. In the event where the employee of CoCo 1000 works on a difference CoCo (say 2000 which does not have the HR module configured) we recharge via the intercompany transaction, and timesheet accordingly.

My Question is, if we were to create a new CoCo say 3000, what will be the benefits of configuring a new HR module against just recharging it to a CoCo that already has HR module. I need to understand the pros and cons in addition to understand the need of configuring the HR module against not doing so.

So if we take the above example of a new CoCo 3000, I need to understand where i can use the same example as above where I can use a CoCo that already has the HR module and cross charge, against if we decide to configure the HR module for 3000.

Please advise.