There is no doubt that Either has a better bat than Phillips. And if you move Either to LF his defense won't be as big of a hindrance as it was out in RF. I also think its much easier to find a replaceable 2b than it is to find an impact bat. Phillips is an enigma to me. Nice pop for a 2b, great D, not good against RHP, and doesn't carry a good OBP. If you were able to replace Phillips with a guy who wasn't as good on D, didn't have as much power, but had a better OBP it may just fit the lineup better. It may allow you to drop Stubbs in the lineup to take advantage of his power.
Its easy to make comparisons based upon isloating two players. But the reality is its how each player fits into the grand scheme of the team. IMO Either in LF + Valakia/Frazier/etc. at 2B is better than Gomes in LF and Phillips at 2b.