Thoughts on NL-Only Keepers

Been in an NL-Only League for 7 seasons.

-Only 8 Teams.
-Allowed to keep up to 4 players, but lose a round for each player you keep.
-Standard 5x5 League

I'm keeping 4 players, so I lose my first four rounds of the draft.

Keepers:
Troy Tulowitzki
Ryan Howard
Jason Heyward
Buster Posey

Didn't keep:
Chase Utley
Brandon Phillips
Lost Adam Dunn to AL


Thoughts?

Last season, traded this year's 5th round pick for Utley in hope for a playoff run, but got hosed in first round.  Thought I would keep him, but shit happens.