First of all, there is nothing official yet. There could be snags...salary-wise (the Cowboys could be offering more money if they are offering the Asst. HC position), and staff-wise (autonomy to hire defensive assistants, etc.).
The things is...with LeBeau's status up in the air, it didn't seem very feasible that the Steelers would make Keith Butler available at this time...Butler was paid handsomely by the Rooneys because he clearly is the DC in waiting.
However, if Horton is hired as DC we get a true Dick LeBeau disciple and a coach who will bring the Steelers' system of 34 defense to Arizona. We also get a coach who knows how to maximize the effectiveness of his safeties...which is a real plus for the Wilson/Rhodes/Johnson trio...especially with regard to Wilson.
We also get a coach who has done his homework on the Cardinals and, like Kerry Rhodes, feels we are a couple of pieces away from being a very good defense. You have to like the optimism there.
Horton should command the respect of the players...and they should be all ears when it comes to learning the Steeler 34 zone blitz packages...
This defense should be much tougher and should tackle with much more authority.
The other thing is there may be a chance he could bring Ike Taylor (6-2, 195, 9) with him...and that would be a very nice addition indeed.
So there are plenty of plusses here...especially that we get a true 34 coach who has learned the defense from the best in the business...and as for calling the defenses and the blitzes, it's likely so ingrained in him by now in terms of feeding off of LeBeau's calls that the transition may be automatic.
I just hope the Cardinals give him the autonomy to hire the right defensive assistants...ones that he feels comfortable with and ones that he knows understands what's exepected from every player in the system.