Its normally regional airport/mil approach controllers who are the worst for it. But there is such huge variations you can never tell what your going to get. It even changes between ATCO's on the same unit.
I don't think its the way it should work either. Nobody would design it the way its being done just now.
But there was a major flaw built into the system when there was no link to flight rules. Which are pretty standard world wide with only the numbers for viz and distance from clouds changing locally for VFR. And its pretty solid in a pilots head which one they are operating under.
When the seperation is more stringent than operating in CAS there is something wrong. Change the deconfliction seperation for all traffic to unknown/IFR and pass traffic info to known VFR. Instead of the current situation of VFR being seperated by 3/5miles on traffic they can see.
Then there is the names of the services, they are so far away from anywhere else nobody who hasn't flown extensively in the UK won't have a clue what they are and opt for the one they do understand which is usually basic.
How about
Flight information service
Radar information Service
Radar control service.
You need to have radar somewhere in the names for the radar services and the "I am speaking to you just in case I need to pass a mayday but don't actually expect anything and also want to do the nice thing so I am known traffic" Is pretty globally known as flight infomation service. And something which denotes you are being vectored/controlled on the top level service. Information always means you have to deal with the information and decide your own actions. Radar Seperation Service might work for the top level.
You can get fancy with english if you like with the names but it will just wash over the heads of any ICAO 4 english speakers like the Taffs and Jocks
Procedural needs looked at so that IFR flights get given a procedural service as standard and arn't asked what type of service they require. Then the current situation of folk getting passed traffic in IMC of whats on the procedure on a basic service doesn't happen. Hopefully this will stop the situation of two aircraft on the procedure with one of them not controlled and in alot of cases don't even realise they are not being controlled and its up to them to seperate themselves. If they can see the airport they will ask for a visual.