Am reading a pdf of core rules. I have played ff's WoW/G and I don't see a similar rule in x wing..

Am I missing something? If not, I wonder why the designer chose not include it.

Complexity. X-Wing is meant to be a very simple, fast playing game and an extra set of rules to govern that was just more complexity than the designers wanted,

I have played both WoG and XWM and it is really bizarre how very different the games play considering how very similar they are on the surface.

I've played a couple of games where tailing is a factor. It could be interesting in X-Wing if it was added, but as Forgottenlore stated, it would add a degree of complexity that isn't really required. The closest thing we have currently would be the Intelligence Agent upgrade. It allows you to know what someone is doing, but you still can't do too much about it.

With movement being made up of your chosen maneuver and then possibly a boost or barrel roll, Intelligence Agent will only give you a general idea of where the opponent is going to be after the maneuver. But you only have to be close to the target to use it - you don't have to be 'tailing' the target.

And there's the forthcoming "Stay on Target" EPT as well.