Four based long haul units isn't a skeleton operation.
US transatlantic is currently skewed to US POS so Virgin are not the strongest of brands to lead that, although in a JV with Delta that shouldn't be a deal breaker. Thomas Cook's strength was high volume UK based holiday traffic which is still there but price sensitive due to the strength of the dollar.
Am not quite sure what you mean by "until Virgin recover". I don't think they've ever been that much bigger fleetwise, even with the B744s retiring early.
10xA330
4xA339
9xA350
17xB789
Total = 40
MAN is stuck between not being a classically attractive inbound destination for US holidaymakers in the EDI/DUB mould and the traditional UK based POS being hit hard by cost of living and poor exchange rate. Double whammy!