Even with crazy venting 5's are HUGE on that dash. My original plan with my Escalade was a pair of 3's up high with 8's in the doors and no tweeter. Do realize, I set my car up solely for me and could care less about competition. I also listen nearly exclusively to live recordings and/or musicians that fundamentally play live even when they record. Being a guitarist and bass player accurate reproduction is paramount to me and I will forego coloration even if it would be judged higher.
That all being said, the dash on my truck and aiming made me feel like it wasn't worth the battle. Have to say I spent a lot more time with my Silverado experimenting and it naturally soured my expectations here so diligence wasn't as good. I also had children by this point while when I had my other cars that was not the case...outside of the ML63 which I left stock as it was leased and warrantied...so I could drive it like I stole it everyday.
I draw no conclusions for you. My problem with your truck (or mine) though is that I don't think a dash install is ideal, personally I am also not a fan of kicks (realize I am 6'7" if I were 5'8" then space considerations would be way easier), which doesn't leave many options in the truck. Not trying to be discouraging, but hey it's car audio everything is a compromise. That being said, if I were in your shoes and really felt like getting the mid up is ideal I would a single driver that can play as much of the audio spectrum as possible. Most likely that would be a 3 or 4 sealed on axis, but chosen specifically for it's FR. The challenge there is the dash hump and keeping the driver low. Based on the space in mine I am not sure I can even see a 4 fitting. I expect you will stretch that the other way though and deal with less of a direct response and compensate with other drivers for not being able to get the mid positioned right. Personally I wouldn't. Of course that means you won't be running a Blues mid if you choose my route as it would be self defeating.
Either way. Throw out all bias's, competition desires, and instead truly focus on what is important to you. What do you need your stereo to do for you. Then build it to do that. Just don't cheat yourself into compromising because you have something. That to me is the biggest mistake I have made over and over and over in my life. Of course to compensate a while back I just bought one of everything which I realize everyone doesn't have the budget to do. For me, I didn't have the time not to. Once you truly nail that desire down things will be easier to decide.