If the average ComGuard person served for 30 years, the ComGuards would require only ~4% replacements per year (the extra allows for people leaving early or dying in accidents). At that rate, it would take 8 years (until 3060) merely to replace the fatalities from Tukayyid.
That sounds more than adequate for a given period of time to replenish losses. Couple a lifetime service commitment (which hasn't been modified for the ComGuard as far as I know), with a significantly (by BattleTech standards) reduced recruit pool, plus new security concerns in light of the Schism and I'm pretty surprised the ComGuard's made any real headway redressing their manpower needs.
Then again, given how the ComGuard simply reorganized their army formations and garrison duties after losing the League and Confederation garrison posts, I have to check, but I don't think the ComGuard ever made good on the losses they sustained at Tukayyid. Material losses maybe, by shuffling around old equipment and filling in the small gaps with new, but I have serious doubts (without looking at the sourcebooks) they were ever able to recoup.
I also question the ComStar's capacity to supply new material goods to the Guards post-Tukayyid. Unless Terra was manufacturing goods in excess to available users and the Word of Blake just inherited a ton of material (doubtful, since the size of the WoB was purposefully obfuscated and surprised even ComStar), then the Terran manufacturing machine was not operating at even half speed post-Tukayyid for even a couple of years. (Say 6 year before ComStar loses Terra 3052-3058, subtract two years for refurbishment of mothballed factories, and it's still 4~ years of intense manufacturing.) Especially, given what we've seen Terra capable of doing during the Jihad, it leads me to believe in the possibility that either the Word of Blake inherited some serious stores when they took Terra, or the real brake to the ComGuard's recovery was manpower.
Not counting the Shadow Divisions, the WoB doubled the number of line Divisions and expanded the Protectorate Militias with locally manufacturing equipment. The Protectorate Divisions were created mostly after the start of the Jihad, so from 3067-3081, while the line Divisions were doubled from 3058-3067 - less than a decade. Even the Shadow Divisions benefited from Terran manufacturing, so the number of new divisions and manufactured material could conservatively be placed somewhere in the 30+ mark. Even averaging the creation of two divisions a year and replacement parts (which we know didn't happen), that's more than enough to have rebuilt the ComGuard to their pre-Tukayyid size. Again, it "seems" like manpower is the deciding factor.
This is funny because the WoB (for the most part) recruitment pool was "hindered" by the same physical limitations as ComStar.
So a couple of possibilities. One, ComStar started the Terran manufacturing ball rolling, but didn't get to enjoy the fruits of their labor when they lost Terra in 3058. This idea might be supported by the notion that ComStar's new Rasalhague factories were able to help resupply the existing ComGuard, but not increase its overall size. ComStar was forced to purchase material from around the Inner Sphere just to supplement the 2-3 factories in the Republic. Given the situation post-3058, this wasn't too different from the six years post-Tukayyid time period while Terra was under their control. Before 3058 and after 3058, the ComGuard was saddled with the same material/recovery needs (only exacerbated a little bit more by the FedCom Civil War), with the primary difference being ownership of Terra. So, as they say, something is rotten in Denmark.
Either Terra wasn't producing, or ComStar couldn't find recruits, or ComStar didn't exert real effort in rebuilding after Tukayyid, or Focht is an idiot, or any combination thereof.
On the other hand, however, we've seen that a number of ComGuard personnel, especially senior officers, were refugees from House militaries -- Focht wasn't the only one, and Focht had had fifteen or twenty years to remake the ComGuards in light of his long service as Freddie Steiner, though it is debatable that he had the desire to do so, or a reason to bring his knowledge to the ComGuards, even though such is exactly why Waterly desired a truly competent military person to head the ComGuards -- which Teddy Kurita happily supplied.
Too true. I mentioned Focht is an idiot, but what that statement reflects is an inept officer's corp. Honestly, I lean more towards ComStar not exerting real effort to rebuild the ComGuards after Tukayyid. By ComStar, I mean the First Circuit.
It would have been in the First Circuit's best interest to maintain, in decent status, the post-Tukayyid ComGuards, but not make good or serious headway against their material losses (even rationalizing it in face of the % salvaged?...). In light of the Schism, rebuilding the ComGuards' manpower would have been hideously and painstakingly time consuming. Fleshing out loyal recruits from the WoB plants would diminish an already small recruitment pool, so sending Terran factories into overdrive to produce usable equipment for a future army of loyal recruits makes sense, but could have been akin to knowingly arming your enemy given the Guards' defection rate. Personally, if this were true, it was a monster mistake. Then again, hindsight is 20/20.
So it's possible the First Circuit declined to produce the massive amounts of new equipment to make good on the losses sustained at Tukayyid, and instead simply increased the manufacture of replacement components and repair equipment. Given the security issues in light of the Schism, I don't really see the First Circuit in a hurry to (re)expand the Guard to its previous size. Either way, increasing component production would have primed Terra's factories for the WoB take-over, and explain some of their massive decade-long expansion. If Terra was primed for intense manufacture, then the Word didn't lose as much time in the conversion process.
Food for thought...