The difference is that Victorino is coming off a major down year. Swisher is coming off a pretty typical year. .272/.364/.473/.837 are all good numbers, as are the 24 home runs and 93 RBI.
I don't know know how you can justify signing Victorino for $1M per year less than Swisher. It's different if Swisher was already signed and off the market, but he wasn't.
Also, that stuff about Swisher's option easily vesting and the deal essentially being a 5/70 is nonsense. It vests based on plate appearances in the 4th year of the deal. If he is still playing well he will get those plate appearances and option will vest, but if that happens it's likely to be good for the Guardians.