True Frabby, but you run up against a specific problem that can occur in wartime- the people with the compartmentalized information end up dead or get drafted to fill in gaps other places. It can cause a situation where command does not know what they do not know- which with gear being stashed off the books can cause a problem. Remember that story about the tanks found deep in the bunker? SOMEONE put them there, but then that person either misfiled the paperwork, paperwork got lost, or . . . the paperwork was never filed in the first place b/c they were extras retained after WWII. Now, all the people involved think they are known about and/or recorded . . . they then sign off on the inventory when they hand their duties over to someone else- signing over buildings & inventories is a big chore and usually the larger the pile is, the less likely someone is to inspect it all.
So easy scenario . . . division gets called up by Kerensky from Random Periphery 1 sending a warship/JS/DS task force that can transport all the division's combat personnel, three quarters of their support staff, and a limited number of supplies (basically 2 or 3 units of fire plus sundries) but cannot take say a battalion of machines. All the satellite bases send the most sensitive items- weapons, ammo, comms, computers, documents, and more- back to the main base which still leaves rations, butt-wipe, laundry, etc. Seriously, look at what happens when a base is closed down and then imagine that as part of a emergency operation. The satellite bases- which can be regional garrisons, training range quarters/motorpool, or anything in between- lock up anything they leave behind with instructions for the local police to respond to alarms. The whole division's equipment would be sorted with the most problematic machines or the ones in/needing refit being left behind. The support staff that stays behind would be working on them and base security would be tasked to keep all the sensitive items secure.
If the support staff had to rejoin Kerensky using civil transport, then I would expect them to disable as much as possible they could not take with them- easiest way is to remove the HD that controls the movement of the mech, basically what the neurohelmet talks to for moving. Mechs and armor might be put in ammo bunker's lowest levels with the entrances collapsed to keep people out.
One important thing to remember, as the SLDF was re-deploying from their bases across human space to go after Aramis, they expected to return to the pre-coup life. Star League officers expected to the bases and depots they were leaving . . . its only as time went on and senior officers saw the SLDF & Kerensky abandoned did they start taking measures for area/material denial.
I honestly think Helm was one of those orphaned commands. Loss of links in the chain of command above the base, maybe left off the distribution of codes & other encrypted communication . . . so it did not matter the CO was sending messages to the SLDF, his intended recipients were glowing radiated embers and the back-up channels ignored the messages since they never made it through the filters since they were not in the latest codes.