How big is the clearance for B2B? Is Beba Melee-Immune? And can't be engineered out of IMM or doctored back up? Or can you say, like, the Igao declares Move, vaults over the edge of the box, and as their silhouettes touch, he is Engaged and can declare a CC Attack, even though you have/should/may place him on the ground as close as possible?
If the Silhouettes aren't touching or intersecting in any way, the troopers aren't in base contact with each other. If you have specific terrain pieces that are causing issues, I suggest using house-rules for those terrain items.
Beba can be Doctored/Engineered - you can move through friendly troopers and it is fully possible to make run-by Doctor/Engineer declarations. Not so with Engaged because the trooper will stop immediately on making contact with an enemy and that position does not fulfil the requirements set forth by the General Movement Rules for the base to be fully supported.
