If it were the case that you could turn out new equipment with a few TL 15 makers, then there would not be anything but TL 15 worlds in the Imperium.
The same way there are nothing but first world high standard of living countries here on Earth...
a few months ago there was a rather excellent thread analysing the true nature of the Imperium, the bottom line is the nobility rakes in more profit by being able to sell TL15 goods to worlds that are restricted to lower TLs.
You can plausibly argue that it should be like that, since by the time period of the game we will probably have achieved a post-scarcity society, but that is not the premise of the game.
The Imperium should be post scarcity, it is the nobility and megacorporations that ensure it isn't so that the wealth flows into the pockets of the shareholders.
TL 15 factories for military production on lower TL worlds are a plausible partial solution, and there is support in Traveller canon, but those will only work by shipping in lots of inputs from TL 15 worlds (otherwise we are doing away with the premise that some (most) worlds are lower tech)
No reason the factory could not make every component needed if fed with the raw materials, provided by local resource gatherers who get paid a pittance... now where have I seen that model...
Indeed during the industrial revolution the pace of change accelerated. If you want to assume it will stay like it is now, we'll be at TL 1000 by the time of the FFW. Which is totally plausible, in fact in my opinion it is more likely to be what happens if mankind actually survives that long, but it is also not the premise of the game, mainly because it wouldn't be a fun space opera.
I agree.
Horse cavalry was successfully used in WWII for certain operations by less mechanized armies, but its use became more and more limited, due to its role being taken over by mechanized vehicles, its vulnerability to air power, and the fact that fewer and fewer people were learning to ride horses. It was considered effective by certain combatants, though others phased it out. Not really relevant to the point I am making because 19th century examples would serve just as well for the point I am making, but I wanted to be accurate. Read up if you want to know more.
I don't need to read up, and that is a disingenuous comment to throw into a good nature discussion.
Horses and other beasts of burden were used extensively during WWII, but they only saw limited battlefield deployment as combat assets, and the result was lots of dog meat.
For example the "Battle" of Izbushensky saw Italian cavalry win a tactical victory over a soviet rifle regiment. A cavalry success... until you read what happened next...
On the last point, I agree they would have stockpiles of TL 15 equipment. However, if you accept the premise that there are worlds lower than TL 15 then you seem to be asserting these worlds must have unlimited amounts of TL 15 gear in their frontier warehouses.
No, they have a limited amount, but sufficient to resupply the Army in the field for what is considered to be the likely duration of hostilities. They have fought four frontier wars, they have prepared for the fifth. The regulare Army, including all becessary logistics are transported via the IN. Only certain world will be equipped to endure a protracted siege or ground war.
Otherwise, their limited stockpiles will run out at some point. Or be blown up or captured by Zhodani. Once the Zhodani have your magic TL 15 warehouses that provide unlimited equipment, you'll be in trouble.
Yes, the ordnance will run out, at which time you have to sue for peace or hope that the reinforcements from Deneb and Corridor turn up. But then, the Zhodani only have what they have brought with them...
Your local factories and logistical chain can only supply so much, but in a war where you don't know where the enemy is until months after they have landed two field armies on your world local stockpile will have to be up to the job or you will be surrendering, which is modelled quite well in the FFW boardgame.
There is nothing magical to a supply depot, I don't know why you want to adopt that debating tactic.
However, if you put those magic bottomless warehouses behind the lines where the Zhodani can't get them, then you're back to the logistics problem - you have to ship it to the front line. More likely, you have a certain amount of gear on hand, and when you run out, or it gets destroyed, you might try to ship in more but you will get disruptions, at which point you either surrender or rely on local production.
What magic bottomless warhouses? Your ordnance is limited to what you have stockpiled based on your pre-war plans. Imperial Army assets are carried to battle by the Imperial Navy, along with their logistics. Local stockpiles are called or at least were called in S:3 waystations:
"lmperial Way Station. A base established for the repair, maintenance, and overhaul of lmperial equipment. It may include provisions for Army troop barracks, naval and scout ship overhauls, and intelligence operations."
The regular Imperial Army is almost absent for the start of the war, with regular units not turning up in numbers until the Imperial reinforcements become available.
The Zhodani have limits to their logistics too, if it comes down to a battle of attrition the Imperial side wins, and in the long term they have a much more robust logistical tail.