I don't think there's an answer to this which would suit everyone.
For example, I've been supporting City regularly since I was 10 and I'm now approaching retirement age so I reckon that over the years I've seen more City games than a lot of posters on BM. I've also been a seasoncard holder since we moved to Eastlands. In the Maine Road days I was a season ticket holder in the old Kippax before it went all seated. I then had a contact in the Ticket Office so I just had a City Card and a group of us all managed to get seats together in the North Stand, no problem. Particularly so when we were in the 3rd Div.
Does all this make me more loyal than others ? Not necessarily.
Whilst I go to every home game, due to business and family commitments (and where I live) the number of away games which I have been able to get to over the past decade has dwindled to maybe 3 or 4 a season. Likewise I can't get to some evening matches (in particular a 6pm Europa League game !) and European away games are an impossibility. Thus, whilst I have a healthy number of Loyalty Points (more than enough to get me to Wembley 3 times this year) I am a couple of rungs down the Loyalty Points pecking order.
I am in the FA Cup Scheme, but for the reasons above I decided to opt out of the CL & CC Schemes and decided to take my chances. Indeed I had no problem in buying my usual seat for the Napoli game, which is what I reckoned on anyway. The same will no doubt apply to the remaining group games.
In which case, whilst it doesn't suit me entirely to see more 'recent' supporters higher up the pecking order than I am, I can't really complain. For example, those who travel away on a regular basis deserve to get first dibs. Ditto if you commit to the Cup Scheme. That's life.
'Loyalty' in this situation is hard to define and I would guess that that there are many others like me who run the risk of missing out - certainly if we get to the CL Final. The only way to solve it for the Cup Schemes is enrol. You pays your money, you takes your choice. We may not particularly like it, but those are the rules.