Geographical concerns...

[Randal]

EB1 did have that constantly respawning rebel force, didn't it? In the form of gold and silver chevroned rebel stacks of alpine and celtic troops near some alpine settlements.

Subduing the Alps certainly is an extremely expensive and intensive operation for any faction in EB1, which is as it was historically. I think it was only Augustus who finally conquered the Alps, before that even though the Romans ruled everything around it for hundreds of miles they did not directly control the tribes there.

[Arjos]

I've mentioned the Alps just as an example, like the Pyrenees and Caucasus mountains had only 2 accesses...
Also how about marshy lands? The Persians never gained fully control of the Nile delta and those very petty rulers' descendants leaded a major revolt before the macedonian invasion...
I've been thinking since EBII will have "populations buildings" couldn't they act as a resource to remove a crossing penalty (representing both harrassing tribes and unknown passes), once those inhabitants became happy with the rulers?

[Diodredai]

Another way would be to use the "desertion" system in MTW:II. Remember: When the Pope signalled a crusade, and you joined the Crusade => Then straying afar from the goal, or not making enough progress/engaging Catholic Christian factions would turn your army into a deserter army, which would slowly disappear due to men leaving your army. This could be through some signifacant modding and trait adjustment be used, to simulate the loss of men due to attrition (in desert areas/cold areas) guerilla tactics used by Germanic, and mountainious tribes, desert tribes exct. I believe due to engine limitations (the lack of infinite turns) simulating accurate army movements is near impossible, however as you mentioned, there should be respawning Rebel forces in small numbers. Another way arround this is the trait system. During winter for example your armies (with the exception of factions who were used to winter combat) recieved a movement penalty. This could be used through some sort of trigger (perhaps engaging one of these rebel stacks in the mountains) the following [which would be used in other, situations]:
Bold move [-25% movement; ?%? of units killed by attrition through use of desertion]
This general has taken on the task of crossing terrain that during this period had little to none roads, suffered from different types of natural dangers such as snow storms, desert storms, the rising of the tide, moorlands, dangerous fauna and fungii, which took a toll on those armies that attempted to cross such dangerous areas.

Then again, if we use the desertion system, we need a substitute for the College of Cardinals, and the Pope, which don't get me wrong would be great, but would take alot of work, and even then intresting bugs would occur, when persay the Swéboz would be told by the Consul of Rome to engage against Alexandria on a whim :P [OFC the EBII team stated they will not use this system/atleast they have denied their plans up about the usage of the Papacy/up to this point to my knowledge]

- Diodredai

[Ca Putt]

I think it'd be funny enough to have some brigants (re)spawn inside the trees along the path - thus ambushing armies that head through this area. No big EBuronum defender stacks but a small stack(3-6) pesky guys that can ruin your day if you're army is not prepared for a battle.

[fomalhaut]

the super stacks that respawn immediately need to be addressed, they are ridiculous

[Arjos]

Those armies spawned to prevent Sweboz, Sauromatae and Getai mop ups iirc...
In EBII that role will be fulfilled by the Boii and Lugiones...

[Ibrahim]

my question personally is: why not implement a true attritional feature (if it's hardcoded, I'm ok with it, but what if it's not)? all that is required is to script a false plague, that slowly drains soldiers from an army. that should make conquest a pain-especially in isolated areas (like east Germany?)

and with false plague script, I mean it works like a plague, but is tied to another trait (like starving, sick, or some other army trait). if you know how to implement a scripted plague (like the one that hits macedon in vanilla RTW), then you can concievably make it for armies on the march (so that say, 10% "die" per season, as in eighteenth century armies)