It's not misplaced at all, and your reasoning for not using all their subs due to fear is flawed.
Herr shipman and fraudiola have got form for not using their three subs for a number of years, often when they have got games well won.
If they were so concerned about players welfare, they would and should make the subs much earlier to protect from injury shouldn't they?
You're argument about them being scared of injuries is frankly rubbish - surely a sub made at the right time helps prevent injuries and protect the players - not waiting until they drop or a couple of minutes before the game end, after running around their legs off for another half an hour?!
You can't keep a sub or two back because you're scared of injuries and going down to 10 men as you have used all your subs - late injuries have always happened - teams just have to adjust and cope with going to 10.
With your argument you might as well save a sub for a late red card against you, so you can change things?!
Klopps a cryarseing tuetonic twot, who mismanages his players by not rotating properly, even though they have a huge squad, and then rushes them back post injury with the aid of the PEDs, and his moaning about 5 subs is becoming really tiresome.
I'm no fan of klopp & completely agree about the cryasreing and moaning. It is tiresome & dull, but it doesnt mean that everything he says is absolute horse manure, a majority is but the odd time he might be right.
Whether they were in the habit of making 3 subs or not doesnt matter when we are in such unusual times as we are, but for the record Liverpool made the most subs of any team last year (85) in the PL with City mid rank (79), however city did make the most starting 11 changes through season, which kinda debunks your "they have got form for not making many subs"
Secondly on the point of "you cant keep a sub or two back" for fear of injury, this is literally what both of them, Graham potter and others have said about this season, saying they can't make three subs earlier for fear of leaving someone on the pitch injured, we were all pulling out hair out when James was hobbling around St.Marys with 3 subs made.
The arguement that you should manage players by taking them off earlier is nonsense. What the stats are showing around soft tissue injuries, is that they are unpredictable and if you could "protect one or two" by taking them off i'd imagine they would, but when it is a lottery as to who is getting injured, the game is losing and edge & subs are no longer used as a tactic within the game, but as injury management. I reference the City V liverpool match in a previous post, they effectively shook hands on 70 mins, the same can be said of Arsenal v Leeds yesterday. there is definitely a valid arguement that they should manage players through rotation, but for me (& 8 PL managers to date) that should be supported by 5 subs.
Regarding red cards, you are right you cant mitigate for every risk within the game, otherwise it would be boring. But for perspective since the start of this season through to the end of last week there have been 116 soft tissue injuries compared to 5 red cards. It's about reducing risk not removing it completely.