That is pretty much the formula I have used with all my successful teams in 2015--and Citizens Bank is the best park to do it in. ALL Citizens teams below
http://365.strat-o-matic.com/team/1424854http://365.strat-o-matic.com/team/1427113http://365.strat-o-matic.com/team/14279303 similar teams here, though SP is not low as 4M--it's still quite low--on the last couple of teams I wanted to go cheaper on SP, but I couldn't get a couple of the cheaper SP I wanted.
I have had success in the other RH leaning park too (O Co.)--but I have been horrible in neutral, pitching or LH leaning parks with 2015 set--generally I can't get the SP I draft this year when I go for more pricey starters--especially Arietta or any higher priced LH. I have managed to snag Grienke on three teams, once as a FA, but can't get any of the other higher priced SP I try to draft with him. It seems any SP below 4M gets bashed almost equally, so might as well go cheap--and, with a couple of exceptions, the 4M to 5.5M ones have not performed for me anywhere near their price point. Warren was good on that 1st team above--but poor for the money spent on several other teams for me.