Both RAK Airways and FlyDubai have received permission to fly to the UK
Did they specifically apply or is this part of a wider EU agreement?
Of the seven Emirates in the UAE, Ras-al-Khaimah is one of the smaller ones up in the north. It is, so I understand, more an industrial centre than an oil or tourist place. With such good quality connections to many UK cities from Dubai and Abu Dhabi, I'm not sure that RAK could compete, unless they offered either (i) services from niche airports like Manston; or (ii) onward connections to regional Pakistani/Indian/Bangladeshi destinations, e.g. East Midlands, Leeds/Bradford or Luton via RAK to Peshawar, Amritsar or Chittagong.
FlyDubai has built a good low-cost network, and I would be surprised if they found anywhere in the UK they could profitably serve, again, given the competition at DXB. I'd see them concentrating as far as Europe is concerned on non-EU, such as further Russian and Ukrainian cities.