There is much to admire about McCoist, as a person and as a football man, and his legend-status among Rangers fans will prove untouchable.
But his gifts as a manager? His team's performances on the field are severely undermining his case.
There is always a knee-jerk reaction after defeats such as that suffered by Rangers against Dundee United on Saturday - this must be acknowledged. The knives are coming out for McCoist, who may well prove his growing army of critics wrong.
But the football evidence is mounting against him. I'm now concluding that McCoist's reign as Rangers manager will not survive the long journey back to the top flight in Scotland. On that road "home" I'll be amazed if he stays the course.
Rangers' current runaway lead at the top of the Third Division is next to irrelevant. What else is to be expected of a full-time club paying (relatively) lavish wages against regiments of part-timers?
"I would be concerned if we were not in a comfortable position in the league, because that is where we'll be judged," McCoist said in attempted mitigation after the 3-0 defeat on Tayside.
Well, I'm sorry, Ally, but where Rangers currently stand in the league is about the least of the factors involved.
Does McCoist's Rangers play an impressive style of football? Does the team look convincing? Do Rangers have the appearance of a well-managed, well-coached team?
The answer to all these questions appears to be "no".
Tannadice on Saturday, following months of patchy Rangers football, was one more glimpse of a team which looks poorly motivated and inspired. As United breezed to their 3-0 win, from a Rangers point of view it was difficult to spot what the strategy was to reclaim the match.
Aside from McCoist's strange desire to play just one out-and-out striker, debating his tactics quickly becomes a dull business – any talented and motivated team should be able to play in various systems and still attend to its business.
It is when a team's play is so porous and fragmented, as Rangers' was in Dundee, that people start to look at the manager.
This current Rangers team, with its smattering of SPL-class players, is an accurate reflection of what McCoist is about as a manager. And the message being conveyed is not good.
In McCoist's defence, you cannot over-estimate the importance of his role as Rangers have plunged into crisis. The 50-year-old has been a sheet-anchor at Ibrox, rallying supporters and, in part, saving Charles Green's skin early on in the drama.
The Rangers supporters severely doubted Green's intentions – until McCoist spoke up in the CEO's defence. Without McCoist, Green's Rangers intervention might have been stillborn.
This is all admirable and laudable. It is another reason why Ally McCoist will remain heroically etched in Rangers' history. But it is not football management.
Last weekend was the seventh successive cup competition, stretching back to July 2011, from which McCoist’s Rangers had been bounced in the early rounds. It is a pretty dire record.
For many Rangers supporters it is painful to criticise McCoist. After all, he was a magnificent striker for the club. His time as manager has also coincided with the club's lurch into administration and liquidation.
As if this weren't bad enough, McCoist had to follow Walter Smith, a pragmatist who seemed to have an antidote to any domestic mess Rangers found themselves in.
But at some stage, the sheer blasphemy of Rangers sacking Ally McCoist may have to come. It is something Charles Green has already considered, and may have to re-visit.
Green knows what it is like to be loathed in football – his time as CEO at Sheffield United taught him that. He would pull the trigger if need be, regardless of the "favourite son" involved.
I hope I'm wrong, and that Ally McCoist leads Rangers back into the SPL. But I can't see it.