Yes that is what I meant by "instead". Action #20 as stated in the wiki is not implemented! and I recently added an additional comment to the wiki for clarification (maybe I should use strike out font on the action_tank etc.).
If the tank is needed for an objective and is available at the start of the map your aiscript must have the global statements in order;
Code:
map_has_vehicle 1 // 0 = No, 1 = Tank/Truck, 2 = Train
vehicle_entity_number <ent> // Vehicle "script_mover" entity num
vehicle_team_owner <num> // 1 = Axis, 2 = Allies
These must be immediately after the global priority statements at the top of the aiscript. The bindlestiff is generally correct as to how close a path of nodes need to be. However you should verify by testing that they will work both for movement and for repair. On v1rocket I found the original mapper defined area for repairing made it necessary to add a special path of restricted connections immediately behind the tank-carrier. Now if you have to make a path pass through the vehicle as I did you should provide another nearby path for the opposing team to attack from (that way when the tank is disabled they can navigate around it). In cases when you have to tweak like this you move the tank ahead by the smallest increment, then switch to the attacking teams (or spectator), go back to the tank add the next node behind it, add the connections, set any node flags, then switch teams again to the team owning the tank, nudge the tank, switch again and add the next node and so on so on etc etc etc.
Now if you want to delay the availability of the tank till after the match has been running then different commands are used inside some of the action test blocks.