We have had couple of reports about cases like this but just couple.
Life has so many variables and when talking about real life sports the teams usually have a lot bigger rosters than we have here. So one player doesn't effect it that much. Then when we go to higher tiers you don't miss games because of work since that is your work. Sometimes life just gets in the way and that's why the re-schedule is there.
I agree you should always have a backup player but sometimes it just doesn't work out:
8 player roster and 1 of your guys is away from home for couple of days, Your backup has a call during the day that he is needed at work even when he was supposed to have a day off and then your goalie hits their head when walking home since it's really cold and slippery outside and can't make it since he had to go to ER. You could play in couple days when your other goalie is back home and so could the other team with some effort but they rather try to get walkover since you didn't contact them early enough even tho you really didn't have that many choices to avoid the situation.
I'd rather have these teams play the game another day rather than giving out a walkover but of course the teams previous actions are to be considered.
If the other team has a record of "cat in a tree, head injury, drove to his friends house instead of his own by mistake" type of reports we will take a look at the situation with that in mind.
If we don't get reports there's no way for us to know about these things. Even if you can settle things it's good to send a notice that
"Team X didn't send any notice and didn't show up but we still managed to settle things. just to let you know"
There's a certain situations where walkovers will be given but walkovers are not given lightly since we are all here to play the game.