I think that if you want real strategic play, then you need reasons why PCs shouldn't always take whatever easy ways out they can get. Sure, luring ogres into a trap or going back to get help might make that encounter easier, saving the PCs some daily powers and surges. But it's also costing them time and possibly other resources, making it a trade off.
You probably don't want to make just avoiding or cheaping out enemies too rewarding. Otherwise the ideal strategy is still preselected; it's just different from the default..
In a game I'm playing now, the PCs are sort of competing with other adventurers - the most successful group clearing out the monster infested gets noble titles to it. Because other groups are presumeably out doing stuff too (plus the enemies might do something too), we want to achieve major objectives as quickly as possible - that means going through enemies with as little surge/daily uses as possible, and maybe bypassing enemies when possible to get to the important bosses. But we also want to take the stuff of all enemies to get treasure, and win all the encounters for XP. Bringing along some NPC cannon fodder/allies would give us an advantage in encounters and allow us to save some healing. But getting other people killed damages our reputation. There are tradeoffs to make - neither rushing in and killing everything (even if this is our typical modus operandi) nor bypassing as much as possible is necessarily the correct approach.