Just fyi - from what I read, thats only one potential reason. Another one has been reported, that when Ruben was in contact with Liverpool that his representative still organized some meetings with Spurs (iirc). That irked people and thats why that didn't happen. The notion that Pool decided against him because of the formation is a little naive though isn't it? I mean, this is the formation that brought him his reputation, it brought him into contention at clubs like Liverpool. I'd say, it is a bit far fetched to act as if they just realised his formation midway through the talks.