Off the top of my head I would say that you'd want to include the tanks as a solid obstacle to be avoided (since that example uses the pathfinding behaviour). This means that paths could be redrawn each frame to avoid each other (since they are dynamic and changing position all the time).
I haven't got chance to try that now, and I'm not sure what the effect will be on your framerate. It sounds as though there might be a lot more calculations going on since you'll have to refresh the pathfinding each frame to take into account the dynamic nature of where friends and enemies are. You'll have to test it and see - it depends how many other objects are on screen, how many of them are using this kind of behaviour etc.
Would someone else be able to comment on this?
Also, please don't bump after a short time - in this case it was less than 2 hours. Whilst it IS very frustrating to be stuck on something (we've all been there, and go back there FREQUENTLY!), this is a small forum with only a small number of people who will be able to help you, so you'll have to wait. I would suggest at least 24 hours before bumping in future. Frequent bumping will only lead to people being more likely to ignore you.
In future, find another problem to work on whilst you're waiting for a reply on this one.
Hope that helps.