After carefully re-reading the last chapters of LAMA for the fourth time (I still can't figure out which side of the forest they're fighting on half the time!) it's clear that HM attacked Roymark with a "sizable" force of infantry, and they captured all the artillery the AoS had in the entrenchments around the town en route to capturing the whole place. They are available and a
lot closer to Thesmar than Ahlverez is.
A relay of riders and spare horses could carry new orders from DE at Kharmych in less than two days quite easily if the allies haven't captured the semaphore. At that point those troops could proceed to Cheryk, notify Hanth's troops and cavalry that Ahlverez is on his way, and be in position to block him wherever he decides to go, which is most likely the bridge SW of Cheryk, the one at Yairdyn, or the one at Trevyr. (And Trevyr doesn't appear on the map in LAMA, nor does the highway from Cheryk to Evrytyn, or even Evrytyn itself! So we're sort of left guessing whether the online map from MTaT is accurate, since they do appear there.)
DE is no longer responsible to keep Kaitswyrth in check - that falls to Highmount and the Army of Cliff Peak. He's already destroyed the Desnairan contingent of the AoS, so he can either move west and help Hanth in his assault, or head north to break out of the Sylmahn gap and destroy Wyrshym with the help of BGV. That would put well over 150,000 ICA and Siddarmarkan troops in a position to intercept the main thrust of the 1.6 - 2 million Harchongese troops that will soon be headed their way. (Did anyone forget that little tidbit?)
The ICN will do a great deal to cut the supplies reaching Siddarmark via the Gulf of Dohlar, but the Harchongese about to invade like locusts are strewn along the Langhorne canal, which will soon be the
only canal under CoGA control that can ship troops and supplies into Siddarmark.
Hanth is spread
extremely thin at this point, and seems to have the responsibility to keep both Desnair and Dohlar out of the war. He also doesn't have any member of the inner circle with him (and he isn't one dang it!) so as well as he's done, he's courting disaster, especially since the next Dohlaran army he faces will be well fed, rested, and armed with better breech loading rifles than his own troops, plus it will have rifled artillery.
If it weren't for the fact that the Dohlaran troops at Evrytyn are at the end of a long supply line that can be cut by blowing up a lock or two on the canal to the west of them , they'd be a serious threat to drive Hanth back. I expect he'll cut off their supplies and force them to retreat - and they won't enjoy facing the Delthak one bit either! (Although it won't be sailing past the 1st lock on the river to avoid being trapped, wherever that is.)
It makes sense to have DE march west and join forces with Hanth, especially if a large force of Harchongese is sent through Dohlar. (Which is what I'd do if I were Magwair.) I expect the Harchongese to be split into two or possibly three armies - one to invade Southmarch, (facing Hanth and DE) one to hit Glacierheart, (facing HM) and the last and largest to sweep from Tarikah towards Guarnak, where BGV would meet them. Toss in 200,000+ Siddarmark riflemen, and although the battles will be horrific, the allies ought to prevail in each - but not if Hanth is left hanging without significant reinforcements. Besides, he needs to capture the Dairnyth - Alyksberg canal and shut off the southern supply route for Kaitswyrth. (Although the Haarahld VIIs will take care of that in a few months.)
Of course how the EoC decides to array its forces depends on what the CoGA does with its armies, and if Magwair decides to keep the Harchongese together (hide your wives and daughters!) they might be enough to envelope and destroy any one of the three major allied forces, with Hanth being the weakest unless DE reinforces him.
