Your on the right map, that's a start.
If your trying something, your on the right path.
Rem pbr spawns out in soldierspawns.con, no more bots boating.
Understanding AI and what it reacts on takes a lifetime.
Making vehicles not used and leave them for humans I know only one way to do.
I use towerspawners for this, look at US Airtowers.
One for AI allows them only to spawn on flag when there is a vehicle where there spawnpoint is.
If they run already, you have to fix pathmap so they can't reach vehicle.
Boats, they are transport vehicles.
If you have one trail that works, you can't get a second one to work.
This files I tweak bots with.
BfVietnam/levels/GameWarden/ai/condition.con
BfVietnam/levels/GameWarden/ai/prerequisites.con
BfVietnam/levels/GameWarden/ai/StrategicAreas.con
BfVietnam/levels/GameWarden/ai/Strategies.com
and pathmaps you have to play with in editor42.
Easy, far from it.
BFV bots and BF1942 bots are far from simular in behavior.
BFV bots are badly done from start, but have more posibilitys then 1942 bots when done correctly.