With any manager (more head coach really, these days) I don't think it is a simple matter of assessing their strengths and weaknesses, at least not in the way they appear after the team has won or lost. Its more about the suitability of their approach overall.
In Glasner, as with Roy before him, we have a training ground coach who drills his team into a settled and well-understood shape, particularly defensively. We are set up to absorb pressure more than to apply it. The system rarely (if ever) changes, and team selection is highly consistent.
When we do well, be it an isolated win, a run of good results, or a trophy(!), the approach seems a significant part of the reason. It gets the best out of a squad that, whilst strong by our standards, is nothing like as good as most of the teams above us. It is smart, modern, realistic, and makes the whole greater than the sum of its parts. When we do badly, however, it seems predictable, unduly rigid, inhibiting, and conservative.
Imagine now that Glasner, or the next man, changes his system more often, either during games or from game to game. He rotates a little more, and makes substitutions earlier in attempting to influence the game. When we win he will seem tactically advanced and alert, attuned to high-speed decisions, bold, and flexible in a good way. He will be making best use of the squad, giving better players the odd rest and allowing the development of young hopefuls. When we lose, however, he will seem like he is jumping from one idea to the other, confusing the players, and not knowing his best XI. We will be sympathetic to youngsters being thrown into an unsettled side without a consistent approach they can slip into and be guided through.
How many times do you see a flailing club change manager, or the manager change systems and selection left, right, and centre, all apparently out of desperation? It often seems like luck when they get a result, and if anything just spreads doubt to the players, fans, and media about the sound planning and clear-headedness of the coach.
To me, that is how football is. Each different approach a coach may bring to the job has its own characteristic traits in both good and bad spells. And we will always have both, regardless of the approach taken.
So I think the question is, what approach, overall, is best for Palace? I remain convinced that a settled team and system, largely focused on defensive shape, is best. We do not have the first XI players or squad depth to justify either taking the handbrake off, or rotating. We have had a shocking result, and are in a bad run of form, but that doesn't mean it is all broken. The underlying factors remain the same, and the best approach remains that which we currently adopt. I expect Glasner to play 343 with senior players in the coming games, and would be concerned if he didn't.