Not quite true and not totally objective.
On Friday night, our group of 6 3rd level PCs took on 2 higher level fighter types (2 attacks per round) in plate armor riding on warhorses in plate (who could trample PCs and knock prone), 2 higher level archer types (two attacks per round, hiding in trees firing long bows from far away), 4 dogs (mastiffs or some such), and 2 skirmishers (not sure of level, but it took 2 or 3 hits to take them out and they had pack tactics, hence, advantage).
This was not us being led around by the nose at all. It was our third fight at the rear guard camp (HotDQ). Fight #1, we took out the rear guard. Fight #2, we ambushed the group sent to check out no response from the camp. Fight #3, we tried to ambush the second group sent, but they ended up mostly ambushing us. Not only were we not really able to detect their presence until they were right on top of us (my wizard was watching long range with his familiar hawk along with two PCs in the woods watching for them), but when they did show up, the DM played them very smart (i.e. they did not go anywhere near our trap). If they looked too powerful and/or numerous, we had originally planned to avoid the fight completely, but the DM never gave us a chance to do that. We were basically forced to fight or die.
So, we were outnumbered 12 to 6 with at least four higher level foes and multiple foes with mega-powerful attacks. I don't know exactly how much more powerful they were than us, but it did garner us 350 XP each.
We ended up winning the fight, but it was obviously heavily stacked against us by the DM and it could have easily led to a PC death or more. As it turned out, our fighter and cleric are now wearing plate armor. Woo Hoo!