Could it be done? In short; yes. Sustainable? No. Would it take you a loooooong time and massive effort to get to this point; Oh god... yes.
Just because this has been going on for so long, I will add the facts, because I disagree with both the above statements:
Did one town ever do 40k in a tourney? NO
Is 40k points by one town possible in the old tourneys? YES! He needs to have exactly 149 steel provinces (or whatever tourney you want to do that in). In the old tourneys the only limiting factor is the number of available provinces, nothing else. I seriously doubt anyone in this game has that many Steel provinces, which is why nobody has ever actually done 40k points. I will not do the math on if it in theory is possible that anyone has that many steel provinces, how many rings out from his city he would have had to go and how long the scouting times will be then...But I assume in theory someone who started playing the game when it came out and prepared from day 1 for doing a 40k tourney (that means years before tourneys were even invented) could have gotten there
Is it sustainable or even difficult? Of course sustainable and not at all difficult, if you have the 149 steel provinces. I could have easily done them all every week and if I had had that many provinces. However I had to scout steel provinces 5 rings further out than my other provinces only to reach 75 Steel provinces for 20k points.... doubling that would have taken me years worth of scouting.
20k by 2 towns is no problem at all. We had 3 towns with 20+k points last steel I think, one of them did 20k two weeks in a row. (he had 75 Marble and Steel provinces each)
Time does not matter at all. Once you have tourney cooldown time reduced to 0, it only matters how fast you can click. And you had to click a LOT. Once 4 of us got together at the start of the tourney (plus others doing their first round) just to see how fast we could do it. took us 1h 32min to reach 10 chests, 4 people with burning thumbs/index fingers is the only benefit of this exercise lol.
The stupidity of this insane clicking is the only reason why I did not do all my provinces 6 times every week, often I stopped at 50 provinces (13.5k points), just because the clicking was so insanely mindnumbing. I didn´t even need to time boost troops for that... and this is also the reason why the new tourneys (as bad as they are) are still much better than the old ones
It is not annoyance with clicking that stops my tourney now, but actually a point where I find the resource input too high to continue. A much more sensible approach.