Having three 1B centers is better then having one 1st line C, one 2nd line C, and one 3rd line C. There's also the fact that you don't need your centers to be your best players. Chicago's big 3F were 2 wingers and a center. If Caufield can consistently reach or be close to 50 goals and we say draft Michkov who can also score 40 goals then we would have one of the leagues best forward groups even if are centers are closer to being 70 point guys then ppg players.
I'd also point out that you can't assume that sometime in the future when you want to go out and spend your cap space on good players that there will actually be a guy who will sign with you. Assuming you can get a player as good as PLD via FA in a few years is not a good assumption to make. We can't just ignore the fact that we've historically struggled to attract top FAs. There have been a few for sure, but more often then not we are the bridesmaid and not the bride. So we very much risk wasting prime contending years trying to get a FA to put us into that contender status which is far worse situation then getting that FA a few years before you are ready to contend.