Well, 5 min rests or similar time were a thing in most battles in non-modern world.Yeah I mean, it went off the assumption that people stop, look around, bind wounds, etc. between encounters.
Although if you actually do run into multiple encounters back to back in 4e, you're probably going to die. Had that happen twice, the first time was a very long slog with several characters near death. The second was a TPK.
Basically, 4e assumes you have no reason to hold back using Encounter powers. So you don't. Which can cause serious havoc if they aren't allowed to refresh.
And if you conserve encounter abilities "just in case", battles go longer than they really should. It's a real Catch 22.
The only way around it is to agree with the players they will always get their encounter powers back, which might bother some people's immersion.
Personally, what I would have done is just say encounter powers refresh whenever you roll initiative, and the purpose of resting is to recover hit points.
You could only be in melee combat of shield phalanx for a minute or so before your combat capability falls of drastically.
That's why they had(if they had enough soldiers) front line rotations in battles.
Try to shoot a bow that you can barely draw full length. then try it 10 times. You'll need a breather of couple of minutes.