I've encountered this several times in the Marius-Sulla-Pontus game, where having slingers or archers in a stack really slows it down. Not on every move, but definetly on some.
I have a force in Hispania using 10 out of 12 command points, a mix of legion, auxilia, equites and impedimenta. Time of year is December, trying to move from Toletum > Ilipa. With Funditores and/or archers in the stack move time is projected to be 45 days. Without them, 15 days. I look at the element stats and they have move coeffiecents of .95 and 1.10, which does not to explain the extreme slowdown. Cohesion is at or near 100% good for all units.
Is it trying to move african troops in the winter? I have african equites who do not seem to feel the effect of the cold.
Using the newest (1.01) version of AJE, game files attached.
thanks