So you basically went for an independent command unit?
What was your inspiration for your organisation (I am speaking about the 'Mech one) Foot units? Cavalry? British? American? Soviet? German?
None & all, it's just plain logic. It is completely illogical to have the command element permanently attached to a line unit. when that line unit is in action then either:
the command unit is occupied with that one local action and not doing it's job directing the other members of it's command (and thus leaving them effectively out-of-command) or,
it's doing its job as command and leaving the unit it's attached to under manned,
either of which can be fatal in combat. as such the command unit must be detached. even at Lance level, the command element (mech) is independent of the rest of the lance (and directing them) that is why the Naginata is a command mech not the Annihilator, it can sit back, command and provide LR fire support. The Victor (AC-20 versions) is a very poor command mech (above lance level anyway) because it has to get in close and that takes up all the commanders attention (in the midst of a close range brawl) instead of keeping track of the rest of his units and directing the battle.
One thing I left out was that any unit over Lance/Platoon size can be mixed with units of any type;
So a battalion can have a mech command company and a company of mechs but also have a company of armor/vehicles for 2nd company and an infantry company as 3rd company (which would technically be a combined-arms company - if trained as such). It would still count as a 'mech' battalion but would actually be mixed. this would go for Regiments as well, hence the versatility. The books hint at mixed units but report them as 'attached' vehicle and/or infantry battalions but there is no reason they wouldn't be a full part of the TO&E.
My standard Fire lance uses the T-Bolt as the command mech, heavy armor and LRMs/LL for LR fire and also has lots of close range weapons to discourage lights from trying to close and pick on him.