You posted this in the wrong thread, but quick couple of points:
There is a measure of variability inherent to the WAR calculation, but that variability is minor and doesn't limit its value in direct player-to-player comparison, especially speaking in broader terms.
And the real problem here is that you were quoting WAR values without even using FG WAR before, or an assesment that connects to the actual value WAR assigns to players, now you're using FG WAR as the benchmark when another formula was being used in direct criticism of Porcello. I noticed both these issues (Lack of understanding of the inherent difference between formulas, and how WAR is actually calculated, because the offensive, defensive and pitching measurements don't fluctuate as much as you think they do).
If you use FG WAR as a benchmark (and it's just a benchmark), a win is worth just North of seven million dollars (win value calculations have a bit of year-to-year variability, but this is expected given the nature of baseball economics). The point Kimmi keeps trying to make (and real life reflects this) is that pitchers with Porcello's profile (Shark, Leake) are making similar money for more years than what Porcello is making. Is he overpaid? Hell yeah, they overpaid in money to slash a couple years off the contract. Does this mean he can't provide enough value to justify the contract? Nope. He hasn't thrown a single pitch with the actual extension money attached to him, and given market dynamics and past history, you can safely assume he'll be at least relatively valuable, if not as effective as his contract says he should be now, but with the current salary escalation, he might be as soon as next year, even if he reverts to just career averages.
In general, this is a circular discussion anyways. You don't like Porcello, and you have made that abundantly clear. The problem is that you not liking him and him not living up to his contract are entirely different things. The former is a certainty, the latter we will have to wait and see so we can come to an actual answer.