Hmm... are you sure? I was under the impression (just from my experiences) that the actual movements are dependant on the relative positons and angles of each - if you only go for the target, yeah, it's mostly the game just wibbling it about a bit, but I've done some interdictions from some weird angles, and it's made me win it quite quickly if I actually pointed myself in front/behind the ship I'm pulling over a bit, as opposed to directly at them (This is from the attacking side though, not as sure about the defending side). Could well just be me though.
I guess we can't be completely sure of the mechanics involved.
I'm sure groups of PvPers might've experimented with different things to see if they had any effect but we can't understand it fully 'cos it's up to the game to generate the circle-thing.
Point is, there's very little player agency involved in the mini-game.
For the most part, you just chase the circle and if you do it well you win.
About the only agency a player
can apply, is to head for a planet or star so they crash out of SC before the interdiction is complete.
Even if we assume that the attacker's circle-thing
is showing them the optimal vector required to complete an interdiction (which I'm
seriously dubious about), the target is stuck with simply chasing a circle-thing of their own, rather than being given the freedom to do other things to evade the interdiction.
If I'm flying, say, an AspX and I get interdicted by an Annie or a T10, surely it
should be a matter of simply out-turning the attacker to get out of the arc of their FSI - which I should be able to do easily in a ship with much greater SC agility?
Instead, both participants are stuck with the routine of following their own little circle-things which appear to be moving around in a matter that's just as challenging for both ships.