2 world wars, 1 world cup Seriously, we get all so wound up about managers, stats, records etc etc.
When you think about it most managers have good spells and shit spells, often with the same club. Even the Special (needs) One. That's why our history shows that when we just pick total randomers with no managerial experience (McGhee, Gooding & Quinn, Parjudas, McDermott, Stam) they perform just as well if not better than experienced managers with glowing CVs.
It's MAINLY about luck, circumstance, momentum, investment, injuries and the players themselves.
Obviously you can have particularly good or bad managers that can help or hinder but I'm at the point now having seen so many managers that i just think it's more to do with things outside manager choice.
Bring in my grandma, I don't care anymore. Any change will be good.
With regards to the other factors:
Circumstance - I'm not sure if this has much relevance at all. Any youth player is willing to show what they've got, they're all chomping at the bit. Plus, it's not just down to circumstance when a youth player is ready. It's also down to the coaching of the player and the mentality brought forward. You mention the point about new dads, newly married couples etc but surely that can also have an adverse effect? You have more responsibilities outside your work etc
Momentum - naturally that does play a role but surely that's up to the manager themselves to generate the momentum in the first place. Or in the opposing stance, surely it's a manager's job to pick them up after a defeat, work on the weaknesses and go out and win the next game? To your motivation point, players should be motivated to play any game of football. For the years they've spend training to make it this far, for the money they earn as well. Any manager that cannot motivate his team should not be a manager either
Investment - again it's easier for a manager to have money at his disposal. But at the same time, it still takes skill for a manager to identify their targets and implement them into their style. Too many signings, especially from abroad, often leads to imbalances in the squad. Similarly enough, managers without the money should be able to work with what they've got. Look at Dyche at Burnley. They've spent minimum, he hasn't complained and he's done a great job. Then look at Marco Silva at Everton. Spent millions this summer to find themselves in the relegation zone. Most managers that complain about a lack of funding use it as a shield to hide behind their mistakes
Injuries - yep, this can be a difficult situation for managers. IIRC Farke was without ten first team players a few weeks ago! But what I'd like to know is what percentage of injuries result from training injuries etc...because that can relate more to tactical deficiencies rather than luck. Not explaining it great, but you notice Arsenal used to suffer many injuries under Wenger and now under Emery, their injury list is almost non-existent. This article may help explain what I'm talking about
ttps://www.telegraph.co.uk/sport/footba ... es-up.html Players - as a manager, you can't really compensate for horror shows (Virginia at Wolves, Puscas miss vs Bristol, Swift's red card vs Fulham, Virginia at Hull etc). But many players are under the guidance of their manager. The manager spends "X" hours a week training the players up to what he wants. If it's purely down to a lack of effort, then it's 100% on the players. But if the players are struggling tactically, that's down to the managers IMO
Overall - I think managers are hugely important. Set your team out with identity, structure and balance. Have effective communication with your medical team/coaching staff to reduce injuries. Set your methods out clear for the players. Abandon any tactics that clearly aren't working (cough cough Jose). Pick your players up after a defeat, don't let them spiral out of control
It's why most managers are either serial failures/serial successes IMO