In the days of the arquebus, musket, and rifled musket these actions were taken in concert with others in a line - the whole effort was intended to produce a smoothly and rapidly operating apparatus of death that could be rolled over opponents. The manual was generally done standing up, and it was worth learning as armies that were good at it got to go home at the end of the day - still standing up.
It would be well if the photographer who will be in a similar situation could apply the same discipline. First learn what can be done, then learn how best to do it efficiently, then practise this operation until it becomes automatic. It might not be a good idea to roll death down on the average wedding or school sports carnival but the idea of efficiency can never go amiss.
This means going into battle...err...wedding...knowing that the camera is set to the correct WB and ISO and knowing WHY you have chosen those values. Knowing that the lens is the right one for what you do, and if you use flash knowing that the flash has fresh batteries. (And knowing that you have another flash with fresh batteries literally within arm's reach...) Knowing how you will hold the camera for each shot - and that means long practise on the drill field for each posture. Doing professional work while balanced on a bucket is all very well but leave it for acrobats at the Moscow Circus.
It means knowing what to shoot and when to shoot and being in the right place to shoot. No sense peering round a rock in the middle of the church - face the enemy squarely and shoot to your front. Wait, that could have been put better...actually, no, it couldn't.
If changes are needed - putting up ladder sights on the battlefield or altering the WB or ISO in the photo shoot, know where the alteration will take you.
And in the end, when it is all over, remember that no prudent infantryman goes asleep with a fouled musket - and no good event photographer tosses the camera bag into the corner and expects to download or upload the next day. If it needs doing, do it now and do it yourself.