Sorry TennisMom doing posts at speed never a good idea. I should have been much clearer.
Taking your last point first. Yes I meant that Highgate is the fall back for some, in case they do not get WUS or CC. We know plenty of families where the children have sat for say 4 or even 5 schools. For some of these families they want WUS or CC but have Highgate or say UCS as a fall back. That is not to say that some people would not choose Highgate above any schools - there are always exceptions as comes down to personal choice and what you think will suit your little one at the end of the day.
My understanding from the Head is that they will "over" offer on 1st Feb. So they may issue say 80 offers in the first wave to get 50 acceptances. This is because they make a judgement about offers they make which will be declined with input from the other schools. Mr James even went so far as to say that they mark children Offer Accept (OA) or Offer Decline (OD). Clearly it is not clear cut in all cases whether an offer will be accepted or declined. He was categoric that this made no difference to whether they actually made an offer. They will offer even if they expect it to be turned down in favour of say NLCS. But this will alter the number of offers made in wave 1.
They want to get as many people letters in wave 1 because they know many of the children who they want will have more than 1 offer. It is competitive for them as well as our little ones. Mr James indicated that he preferred to get pupils 1st wave offers so that they can make a clear choice between all schools in the first 10 days of February.
They will then run a wait list. He said in past years that they have been down to child 90/100 on their list as parents make final decisions. We would be delighted with a wait list place but not everyone feels like that and they feel that your are "2nd choice".
The number of schools applied to only affects the number of offers made by Highgate, not who they offer to.
I am not sure about the order of interviews. A very good friend has two older children in the senior school already. Her child is being seen this Friday. They already told the family (by phone call Friday) that his marks on the exams were not good enough but were still seeing him under the sibling policy. The Mum told me that at 11+ (which was the entry point for both her two who are there already) then the children are absolutely interviewed in rank order starting at the top. My son's tutor was way less clear on whether the order of being seen had any bearing at all.
Hope I have been clearer this time. This all relates to what I have gleaned re Highgate. The schools all do it differently.
Do you have a child with an interview? When are you there?