Jeff Fisher was a lot better than he is given credit for. He was a middling coach. Not bad. Certainty not good enough to win a Super Bowl with, but the media and public at large typically paint him as a failure and clueless, which is completely false. Most real Rams fans will acknowledge, however, that he played a significant role in dragging the Rams up from being the NFL's laughing stock.
His teams were full of fire, even if undisciplined, and certainly would not lose to any opponent 8x in a row like McVay's Rams to the 49ers...
His teams usually finished around .500, give or take a game or two, but did it almost every season with a backup QB, as Sam Bradford was perpetually injured for seasons in their entirety. If we are being honest, how many head coaches would have done much better, if you consistently robbed them of their starter? Perhaps Bradford's bum knees were a blessing in disguise long-term, as if he stayed healthy, and the Rams did not consistently turn to names like Hill, Davis, and Clemons (what a list!)... we likely hover at or around 10 wins for some time, and we likely miss out on McVay.
We are much better off with McVay but Fisher was competent and, if McVay did not burst onto the scene to such great success, I am sure Jeff Fisher would still be employed in the NFL. I really think McVay's instant success soured the public's perception of Fisher to an unwarranted degree.
EDIT - I doubt he would ever be interested in a DC position. Especially not in LA as subordinate to his replacement in McVay. But imagine if we could replace Morris with Fisher as DC? Bonus points is that Fisher's obsession with a strong running game and ability to scout and get the most out of RBs could really be a great foil to McVay, if permitted to have any input in the running game. Fisher's RBs always produced, regardless of pedigree, and usually fell off after leaving town. Tre Mason. Zac Stacey. Gurley. Steven Jackson. Benny Cunningham. Daryl Richardson.