Which suggests that the AI of smaller factions (1-3 provinces) is rather hampered by the realistic movement mod, rather than helped by it. Of course this is a natural outcome. Also, because movement is greatly increased, AI will probably find it easier to send its armies to do something somewhere. Bear in mind that the AI completely forgets about its plans when you load a game (!), which has the unfortunate effect of leading to a million and one stranded superstacks. This of course will be more of a problem with lower movement speeds, due to the time (and reloading) involved. Hence those triarii stacks doing nothing. Realistic movement mod goes some way to eliminate that particular problem and eliminate said stacks as well, due to them being used!.
Major factions will find it easier to send fullstacks somewhere, while smaller factions lack the economic resources to compete with the fullstacks that are sent to them. Hence Lusotanna being owned. Their economic basis is too limited to compete with the bigger factions around them. Upkeep costs are much less of a barrier to bigger factions than to smaller factions (if it would take you a year before a superstack saw some action, that could well mean an additional cost to your treasury of 25000 Mnai, due to upkeep). This is completely consistent with the SPQR being the dominant faction in Europe (it is the biggest faction in Europe, and the only real competition is locked in a three way war in Greece). Thus the realistic movement mod may have the effect of making money scarcer for smaller factions. They can get rid of more expensive troops more easily, but they also need the troops more, since a new superstack from Carthage knocks on the door every 3 or 4 turns for Lusotanna.
Sweboz suffers from the problem that too many roaming superstacks are within its reach. Beat one, and another one will defeat them. As far as I know, the realistic movement mod does nothing to increase the speed of recruiting, so their bank account takes quite a hit each and every time they have to raise a big stack (due to upkeep).
Only way to know for certain is to disable fog of war, and follow all AI factions to see how they are actually doing, rather than taking a peek every now and then.
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