You and your group have been through a massive battle with a large group of zombies, your two way radio is going nuts, a scout from your group has spotted yet another large wave of zeds headed your way. You notice that some of your group has been wounded, or has become completely exhausted from the fight. To ensure the survival of the remaining members, would you ditch the weakened members, or would you instruct members of your group to not fight and help carry the wounded even though not leaving a man behind could jeopardize the group's chances of survival since now you are moving significantly slower than before. Also, instead of fleeing, how many of you would stand and fight with hopes that after this attack, you will be afforded some much needed R&R. For sake of argument, the zombies in question do move at any pace, some crawling, some walking, others running, though, none very coordinated, so climbing stairs and ladders and negotiating simple obstacles is still an issue to them.
This depends on the wounds. Are they bites or wounds from other various sources?
If I have 20 mins the non injured would still be evacuated and on the route we would assemble barricades and choke points. Assemble 2 or 3 battle groups depending on numbers and choke and burn, then fall back making large kill zones to slow and condense the enemy. Hold the line as much as possible while the majority get out of the area. One person alone can do massive damage by whats known as a collapsing defense or bottle neck defense.
Truly the question here can be considered tactical, but in my opinion it is a non-issue. Assuming they haven't been bitten/infected, the wounded or weakened will have to be evacuated. Regardless of risk, if they want help they must be given help. If we leave behind the few for whatever reason, especially for our own survival, we lose our humanity bit by bit. Soon enough we would be no better than the zombies we fight, in essence killing humans to survive. Just as simple if someone has been bitten, just a 59 cent round.
Can't spell Slaughter without laughter.