Neither of those can get in the team. A better comparison would be Silva, De Bruyne, Sane or Sterling.
Delph played in their CL quarter-final did he not?
I know he isn't a regular. But every 'big' team needs a squad. They'd see Ross primarily to come in and play that role as back up for any of the four players you mention above - and City will have enough games to ensure that still means plenty of game time.
So, let's say hypothetically it was City who are interested. Ross would be weighing up whether he wants to go there, play (probably) in the CL and under the world's most renowned manager and double his salary
or
Stay at Everton, where he has improved a lot under Koeman, and be a first team regular and still be on a very very decent wedge and hopefully be one of the driving forces behind getting us to the CL in the next year or two.
To us, the choice may seem simple, but let's face it, it's a short career for a footballer and Ross may not be thinking the same.
Either way, he needs to let the club know before they all go away for their holidays - which is basically what Koeman said in his presser.