It obviously goes far deeper than who has ownership over the UK's aircraft. The army has no, or very few, airspace battle management SMEs & as a result, they have Fighter Controllers working with them in quite a few areas, helping army folk understand caps & lims of CAS etc etc.
Should the RAF merge with the army, the emphasis would move away from air power & those of us who were 'ex RAF' would certainly be looked upon as 2nd class personnel.
Not sure if I would go the other way and take the a/c away from the army mind, they seem to be doing a bloody good job with the Apache.