Dratini and Timburr should both be A, as they are two of the bulkiest set up late game mons out there right now and both have a niche against certain teams.
Abra and Axew are both great candidates for B, as far as I'm concerned.
Diglett has really dropped off in my opinion. I can see its use merited alongside Scraggy with Memento, but I don't think the metagame today is offensive enough to merit consistent Diglett usage. IMO, C tier.
Don't count the days, make the days count.
Katakiri: How did you even get into this university?