One reason these encounters are a little tougher is because I increased the power of PCs via houserules.
EVERYONE is considered to have a 20 in every stat for purposes of attacking only (thus, they have a base +5 to an attack, before weapon proficiencies). EVERYONE gets a free racial feat. EVERYONE gets a chance per round to recharge MISSED encounter/daily powers (IF they do not use any effects/Miss effects from their daily powers).
So they have a good chance of hitting, and are pretty much always going to hit at least once with their Encounter/Daily powers. They're fairly powerful, offensively speaking.
Thus, I feel a little justified to hit them fairly hard.
The sixth character is a Hybrid Invoker]Cleric. His invoker powers are Divine Bolts and Thunder of Judgment, so no blasts/bursts, but multiple target attacks. (His cleric powers are Astral Seal and Beacon of Hope, so a "Weaken all enemies" daily and a -2 to Defenses AW is going to move things along well).
While there is no dedicated controller, there are multiple characters with secondary controller roles.
The paladin is a Dragonborn, so we have a close blast.
The barbarian is a Thunderborn barbarian, so he has multiple blasts (one of which is an AW).
The fighter is a Tempest, so two-target attacks are a given.
EVERYONE is considered to have a 20 in every stat for purposes of attacking only (thus, they have a base +5 to an attack, before weapon proficiencies). EVERYONE gets a free racial feat. EVERYONE gets a chance per round to recharge MISSED encounter/daily powers (IF they do not use any effects/Miss effects from their daily powers).
So they have a good chance of hitting, and are pretty much always going to hit at least once with their Encounter/Daily powers. They're fairly powerful, offensively speaking.
Thus, I feel a little justified to hit them fairly hard.

And what is your 6th player? A controller I guess, but is it a wizard or an invoker?
The sixth character is a Hybrid Invoker]Cleric. His invoker powers are Divine Bolts and Thunder of Judgment, so no blasts/bursts, but multiple target attacks. (His cleric powers are Astral Seal and Beacon of Hope, so a "Weaken all enemies" daily and a -2 to Defenses AW is going to move things along well).
While there is no dedicated controller, there are multiple characters with secondary controller roles.
The paladin is a Dragonborn, so we have a close blast.
The barbarian is a Thunderborn barbarian, so he has multiple blasts (one of which is an AW).
The fighter is a Tempest, so two-target attacks are a given.