I have been toying around with potential fixes for this issue. I had tried to counter TerritoryDecay to trigger only when the relevant territory was owned by an actual enemy, preventing neutral or one-sided allied barrack influence from draining capture points during a ceasefire. That had mixed success so I then attempted to block CC placement within 200 meters of another placed CC and I think I might prefer that method as it would also reduce arguments in-game when people place too closely together.  I'd appreciate feedback / thoughts from players. 

Screenshot ideas below for what I had been thinking for re-using the top ribbon space, or a kinda dropdown from the diplomacy icon

@lilypoppy, a few things: towns in Carpetania would be aligned with Rome (that's why Viriathus is raiding in the first place), not just Toletum, which should be on the southern shore of the river Tagus. Complutum should be between Segobia (both north of the river) and Segobriga, look at the previous map I sent. I lowered the river a bit (doesn't have to cross the map right through the middle, you can lower it more), and switched the lone port with Toletum (which could also have a more protected port). All has been placed now to encourage exploration, the optimal path shown in arrows. My red dots are from where Roman armies would mostly spawn, you can put their camps wherever you want. 1) Raid south of the Tagus to gather resources (particularly around Segobriga), while avoiding and distracting the Romans. One has no builders and still doesn't control the CC at Mount Venus. 2) Capture the port and build ships to cross (historically I guess they just swam, but their actual path seems similar to how I set it up now, check a previous map). 3) Capture the Gaia CC at Mount Venus (one was previously hinted that's an easy picking surrounded by resources). Romans keep coming, and they should have no problem crossing the river. 4) Continue raiding to accumulate a certain amount of loot, which is the first real objective. When this is achieved, one is told to reach the Arevaci, Titthi and Belli camps to know what one has to do to turn them neutral (not allies, since in theory this scenario ends with Roman victory, and the convincing of the tribes comes after that, all explained in the intro of the next scenario). 5) The requirements for each tribe could be something random among a list of possibilities, otherwise one would be too prepared beforehand. For example, a list of possible conditions could contain the things you say, and also: give them certain resources, research certain techs, bring them a certain number of certain units to a certain point, and so on. Hopefully a script can be made where each of the tribes (Arevaci, Titthi and Belli) gets assigned a task that they'll ask of you for their neutrality. 6) The scenario is won if two (or all three even, depending on what's decided) of those tasks are completed, and the corresponding tribes become neutral. All while the Romans by this point are almost impossible to stop and are overrunning everything, so all is a race against that. Hopefully you are happy with that!

@ Thalatta It's a great pleasure to collaborate with you!

@Thalatta  Map Changes: Design Note: Tribe locations have been redistributed across the region to encourage full map exploration and ensure a smooth gameplay pace. Red dots represent Roman camps that must be bypassed or raided. Objective: Unite local tribes to secure the northern flank while raiding heavily fortified Roman camps (red markers) for resources, technology, and treasure. Faction Missions: Titthi: Gather resources in the mountains to construct a strategic fortress. Arevaci: Attack and destroy a targeted Roman camp. Belli: Sabotage Roman supply lines to weaken their influence. (1,000 units of metal, 1,000 wood) Northern Passage: Break through the heavily guarded Roman port to access the northern flank. Stealing a Roman ship is optional but significantly speeds up your movement across the map. The player is faced with the fact that the port is inaccessible and must reinforce their forces to cross.