Over extremely hilly terrain. Army on flat terrain makes 2mph (baggage trains slow everything down, so armies travel at the rate of oxen), w/ good roads it might manage 3mph. Human walking speed is 4mph. Over the absurdly hilly terrain of Elbreth with almost no good roads, you're looking at 1.5mph. In Eelspine, you might manage a mile an hour with an army. (I'm on a break, shh.)
But mostly it's because I wasn't that familiar with the scale myself. My original estimate was that from Vasir to the southernmost Samkhet Isle would be about twelve hundred miles (roughly the distance from Antwerpen to Riga, so the northern coast of central europe), but that would make the distance between Sheepstead and Miring something in the region of 1/8th or 1/7th that - maybe 150miles? 200m?
So if it takes 100 hours to take an army from Sheepstead to Miring @ 8hrs/day... you actually should be able to manage it in 12 and a half days. Make it half a month, which means armies should really be making travel in the region of maybe 6 provinces/season. I
think that would bring it in line with caravan speed, so how about we give them the same rate of move?
Looks like we'll be revising the distance armies can travel from hereon in! 6 provinces/season, more or less, but
when I get back I'll add a move bonus in to Scout and Cavalry units.
Edit: By this logic, Eelspine is either getting split into 3 provinces to preserve the limitations on move speed or we'll make travelling through mountains take double move.
Hmm... if all that land is mostly PC controlled eventually we're going to need a hell of a lot of resources for managing the game.
Automation will be our friend. Expect more spreadsheets eventually.