BA fleet mainline today 234 (+3 772 due to enter service)
Two B757, two B747, and all B733 have been removed. Two B735 remain until autumn.
On order 8 A320 replacing 10 757 in next twelve months and 6 B77W which will replace further B744s.
Mainline fleet will remain static at around the 235-240 for some years yet.
Those A388 and B787s will be delivered eventually.
BA Cityflyer 10 (Was 12 but one hull lost and one wfu)
Due to be parked all the RJ and replaced with 11 EMB175/190s again no real growth.
Summary BA fleet is 246 NOT 300+ Thats a LOT less
As for the grand father slot lease allocation at LHR the value might well be lower than you think.
There is NOT a huge list of operators wanting to come to LHR.
No South Americans,(they look elsewhere Madrid/Frankfurt) ,no Africans and just about the only Asian carrier wanting access is Vietnam and thats held up at inter-government level.
Only a few of the US operators are still looking for better slot leases and thats happening behind closed doors and within Alliance partner trading.
As for having the holding company based in Madrid -so what its certainly more economical than London, however BA will still be UK registered and base and offices WILL still be Heathrow/Compass House/ Waterside.
Having said that i generally agree that BA financially will be the lesser partner in the merged business.