Quoting FG, League-average WAR rates vary. An average full-time position player is worth about 2 WAR, while average bench players contribute much less (typically between 0 and 1 WAR). Average starting pitchers also are worth around 2 WAR, while relief pitchers are considered superb if they crack +1 WAR.
For position players and starting pitchers, here is a good rule-of-thumb chart:
Scrub 0-1 WAR
Role Player 1-2 WAR
Solid Starter 2-3 WAR
Good Player 3-4 WAR
All-Star 4-5 WAR
Superstar 5-6 WAR
MVP 6+ WAR
In my book players just above average are not No. 2s by any means. In other words, players around 2.5 WAR are closer to avg pitchers (2 WAR), than very good pitchers 4+ WAR (No 1.).
Anyways, if you think that Porcello is already a No. 2, it's ok, but IMO your standards are a bit low.