Concerning pick lists

[Imp]

Firstly will admit being lazy as have little idea on how work but help with the following please.
Firstly the Guide mentions
"2) Never alter the core dates of an existing Camo Workshop OOB formation - by all means, extend it back or forward, but never shrink the time band it is available for."
I take this to mean any existing formation.

What I want to do is make a second Russian OOB which is less MBT intensive picking more formations
122 BTR Co + Tank Platoon
126 BMP Co + Tank Platoon
186 Light APC Co + CS tanks
My thoughts were to copy these formations to say
400/401 MBT Co
Also Possibly
6 Rifle Co
89 Rifle Co B
I would leave MBT platoons as is so could still pick.
Am I on the right path or do you have any suggestions for which formations to replace so it uses these as the basis for its force more frequently.
If possible still letting it throw out a more traditional force mix from time to time
Thanks & realise I will have to test