this may be simplistic, but if trout steals more bases, that leaves first open, and pujols is going to get a lot more walks. without a big bat behind pujols, the chances for him and trout to just waste away out there on the bases is going to be quite a bit higher.
maybe when hamilton returns (and hopefully picks up right where he left off with the bat), trout may be able to steal a few more bags because there's some protection behind pujols.