Let's analyze the scaling behavior of the average number of hits it takes for a 4E Essentials fighter (both knight and slayer) to kill a monster, with some very egregious extrapolations. (We will ignore "Power Strike" in this analysis).
Recall that the average number of hits to kill a monster (N) is the ratio:
N = (monster hit points)/(average amount of damage per successful attack).
The damage done by at-will powers is typically:
[W] + stat mod + magic enhancement + misc.
Stat increases happen at levels 4 and 8, where +1 is added to two stats of choice. We assume one of the stats goes into the primary stat (STR), and the other goes into the secondary stat (DEX).
At the paragon and epic tiers, the stat mod increases happen at levels 11, 14, 18 (paragon) and levels 21, 24, 28 (epic). At levels 14, 18, 24, 28, the stat mod increases are similar to the ones at levels 4 and 8. At levels 11 and 21, the stat mod increases are +1 to every stat.
The magic enhancement for different levels assumes the table:
1 -5 -> +1
6 - 10 -> +2
11 - 15 -> +3
16 - 20 -> +4
21 - 25 -> +5
26 - 30 -> +6
(ie. Magic enhancement increases by +1 every five levels).
To make things simple, we will examine the levels 11-30 of paragon and epic tiers as one entity. Over levels 11-30, the total additional damage contributed by the stat increases and magic enhancement is +7, due to +3 from stat increases and +4 from magic enhancement, by the time one reaches level 30. (Heroic tier by level 10, typically already has a +6 to +8 contributed to the damage, where: +3 to +5 is from the stat mod, +1 from the two stat increases, and +2 from magic enhancement).
One egregious assumption we will make, is that this pattern of stat increases and magic enhancement remains the same every 20 levels as one goes to higher levels beyond level 30. For example, stat increases at levels 31, 34, 38, 41, 44, 48, etc ... and magic enhancement increases of +1 every five levels.
So above level 10, the increase to damage from stat increases and magic enhancement scales approximately as: 7*(level-10)/20
Another egregious assumption we will make, is that the damage of at-will weapon attacks increase as follows.
Slayer
(extrapolating the heroic, paragon, epic "mighty slayer" class ability)
level 5 --> 2 + dex mod damage
level 15 --> 5 + dex mod damage
level 25 --> 8 + dex mod damage
level 35 ---> 11 + dex mod damage
level 45 ---> 14 + dex mod damage
etc ...
(extrapolating the "battle wrath" stance)
level 1 --> +2 damage
level 11 --> +3 damage
level 21 --> +4 damage
level 31 --> +5 damage
level 41 --> +6 damage
etc ...
So for a Slayer always using the "battle wrath" stance, the average damage scales approximately as (above level 10):
avg[W] + level*14/27 + 1 + D + 7*(level-10)/20
where D is the dex mod at level 1.
Knight
(extrapolating the heroic, paragon, epic "weapon mastery" class ability)
level 5 --> +1 damage
level 15 --> +2 damage
level 25 --> +3 damage
level 35 ---> +4 damage
level 45 ---> +5 damage
etc ...
(extrapolating the "battle wrath" stance)
level 1 --> +2 damage
level 11 --> +3 damage
level 21 --> +4 damage
level 31 --> +5 damage
level 41 --> +6 damage
etc ...
So for a Knight always using the "battle wrath" stance, the average damage scales approximately as (above level 10):
avg[W] + level*5/24 + 2 + 7*(level-10)/20
On the monster side, the hit points of various monsters from page 184 of the 4E DMG1 are (assuming this is the same in the 4E Essentials DM Kit box set):
ROLE*(level +1) + CON
where ROLE is:
Artillery, Lurker --> ROLE = 6
Skirmisher, Soldier, Controller --> ROLE = 8
Brute --> ROLE = 10
(Elites double the hit points, while Solos quadruple the hit points).
Now the average number of hits to kill a monster being attacked by a player (of the same level as the monster) is approximately the ratio (for a high level):
Slayer
N = [ROLE*(level+1) + CON]/[avg[W] + level*14/27 + 1 + D + 7*(level-10)/20]
Knight
N = [ROLE*(level+1) + CON]/[avg[W] + level*5/24 + 2 + 7*(level-10)/20]
Taking the level to infinity, the ratios approach the limits of:
Slayer
N -> ROLE/[14/27 + 7/20] = 1.15*ROLE
Knight
N -> ROLE/[5/24 + 7/20] = 1.79*ROLE
For a skirmisher monster (ROLE=8), on average it will take a Slayer around 9 hits and a Knight around 14 hits (without "power strike") to kill the monster as the level goes to infinity.
Let's compare these results to the older Heinsoo 4E classes.
It turns out the 4E Essentials Slayer using "battle wrath" without using "Power Strike", is approximately equivalent damage-wise to a non-striker Heinsoo 4E class using a weapon with damage dice [W]=d10. The 4E Essentials Knight using "battle wrath" without using "Power Strike", is approximately equivalent damage-wise to a non-striker Heinsoo 4E class using a weapon with damage dice [W]=d4.
