From one standpoint, calling up recently-signed Xavier "University vs. De" Paul makes a ton of sense. The Reds need a lefty bat and, with Frazier on infield duty, adding another OF could be a help. Especially one with experience in CF. Paul has played 278 games in CF in the minors and 10 in the majors.
Paul has platoon splits in the majors and minors that favor him hitting right-handed pitchers - something with which both Stubbs and Ludwick have struggled. He's also hit well in the high minors - and especially well at AAA. He has a .332/.388/.529 line at Syracuse and Lousville this season and a .323/.382/.508 line across 4 AAA seasons.
He's 27 years old - which is old to be putting much stock in his AAA numbers - but not too old to have a break-out season. He's done nothing in the majors so far, though he's only tallied a little less than a full season of PAs over four years.
So the the call-up makes plenty of sense. It just doens't do much.
Where it falls short is that it fails to address a much more urgent need: corner infield. The Reds' left fielders have been hitting and don't think Paul is jumping the line to make starts in CF.
Meanwhile, Scott Rolen should really not be starting every day at 3B if the teams actually wants him around and productive through the end of the season. (It kinda looks like he might be starting close to every day). Which means take your pick of Valdez and Cairo making at least a start a week at a CI spot. With a close race ahead and Votto's production to make up, the team can't afford even to take a small step back.
Maybe Henry Rodriguez wasn't ready or none of the catchers (Dioner Navarro included) are up to occasional 1B starts. And I'm sure the phone calls going in and out of the front office taking the Votto gap into account. But the Reds have some serious work to do before the deadline.