The Cards have a good shot at a good HC, a good HC will see that, a franchise QB isn't allways a garantee to win SB expect he is called Brady. And even Brady would have lost the last two against Seahawks and Falcons if the D didn't stop the opponent at the end (Falcons after the half, Seahawks Goalline).
The HC candidate has to know how important continuty is. That you need a GM that supports you and helps you to achieve what you need. And he needs to know that he has a stable on RB (DJ, AD, KW, EP, TJ) that are primed to get you a good running game if you have a average to good O-line. If Fitz returns you have one of the top 10 WR on the team as well, a LT that is okay, a RT that showed he can ball. A good kicker and punter on ST and a promising Kickoffreturner and maybe PR in TJ. If you play a type of Patriots offense you have already 2 TE that can catch the ball in Gresham and SJ and small fast WR that can work the field in JB an JN.
So you could argue with a mix of Patriots Saints offense with any half way decent QB you get a top 15 offense with ease.
On D you have the best OLB in the NFL at the moment, the best man to man cover CB some promising Safties and a Nickelcorner in TM, than the up front is servicable to good with much depth. And you have Golden a good 2nd OLB that can get you 10 sacks a year.
So you have a D that when you install the Patriots D type would work just fine and have your top 10 D.
So and ST with any good ST coach you get them top 10 too.
And with 3 top 10 units you normally are a preainal contender ... just saying, this team is 8-8 with many injuries and a new HC could take them at least to the postseason the next years even if CP and Fitz retire.
I think, because of the stability, the continuity, the easy press, the great facility and the owner investing money and an average team that can achieve more this opening sounds alot better than the Colts, Bears, Bengals, Lions or Giants.
Don't get me wrong, yes Raiders may be a better spot, but they took Gruden.
But Giants are a mess, the locker room is a mess, they have more divas than they can get rid of, Eli will be your QB and he is a problem too, he isn't that great and drafting a young QB behind him will not help and Media will destroy you if you get it wrong. Division with Philly, Dallas Washington, as easy as the NFC West, only you are the bottom feeder in the division. 3-13
Colts, Irsay ... than Luck isn't back and who knows how good he will be, the O-line is a mess and they never invested there, and they don't have many great players on the roster. Best division to be in with Jacksonville, Tenessee and Houston, on the other hand, Houston was very strong with Watson, Tenessee has Mariota and was okayish and Jacksonville dispite of Bortles isn't a bottom feeder anymore, so you might not be as lucky as you think. 4-12
Lions are always a mess owner wise, and after going 9-7 with some bad bounces and bad calls(1 game the zebras stole from them) you fire your HC? And losing 4 games with 1 TD or less gosh ... you have to have faith in your power to improve and don't get canned for the same stupid reasons like cadwell (Cadwell isn't the greatest coach but hell he did many good things for the lions). NFC North with Minnesota and Greenbay and Bears as good as the Cards division maybe a bit worse. 9-7
Than the Bears, with a GM that works behind your back, doesn't give a poo about the opinion of his HC and destroys everything the HC tries to achieve with firing him after a decent season. Yeah you have a QB there, but is he as good as you think? I'm not sold on him yet and if you do worse (Fangio is a great DC and you might get worse if you loose him) than you are faster out of Job than you might think. Minnesota, Detroid and Green Bay in your division as bad as the Cards job expect you are the bottom feeder. 5-11
Bengals are a mess from the top, the ownership is dreadfull and you will not improve as fast as you might think, there is an average QB there that will be good enough to get you 8-10 wins if everything goes fine and crumble under pressure or the spotlight. They won 7 games and lost 4 games by 4 points or less with some luck they would have been a 10-11 win team and in the playoffs. And how GM and Owner works there is beyond ... careless. The D played okayish and oyu have Baltimore and Pittsburgh in your division only Browns are 2 sure wins every year (that might be better than the NFC West) 7-9
So at the End, IMHO the Cards job opening is maybe the best you can get if you think long term, because in the NFL you need at least 3-5 seasons to have a chance to win a SB. And that has to be what you are focusing on as a HC. Because the "Not for long" attitude doesn't work for you as a HC but you need a owner and GM that understands that, and Cards do.