I think that many turning up to that sort of game it'd be rather sh*t to be honest.
Pretending to be Orient fans, but singing Ajax songs, be very annoying for any Orient or Brighton fans there.
If it was 100 or 200 maybe. But 2000, the way attendances are in that competition (even prior to the U-21 teams in it), they'll probably outnumber genuine fans of the two clubs playing.
Could have got the money and chased the quirky media/social media attention from the sort of people who don't normally give a toss about Orient/That competition/That level of football, but fair play to Orient for accommodating the real fans.