I think @Axelazon was trying to explain that the Warrior and Paladin make better use of the four attack because they have offensive buffs. (Despite them not really needing it.)
This means that the four attack is multiplied with the other stats, something Knight can’t do alone.
-The average damage of an Acclaim is used here, 247.
Knight
Without +4 Att
370.5 (Damage Per Hit)
5.83 (Attacks Per Second)
2161.25 (Damage Per Second)
With +4 Att
390.26
5.83
2276.5
115.25 (Damage Per Second Difference)
Warrior
494
8.75
4322.5
513.76
8.75
4495.4
172.5
Paladin
555.75
5.4
3001.05
585.39
5.4
3161.106
160.056
This is how much more the additional attack benefits the other two classes.
57.25 (Warrior)
44.806 (Paladin)
So it would be more efficient on the Warrior and Paladin.
As for the speed bonus…
Knight
Without +3 Spd
7.73
With +3 Spd
7.95
0.22 (Tile Per Second Difference)
Warrior
11.6
11.936
0.336
The difference between how much more tiles per second gained for the Knight and Warrior is this number.
0.116
This means the Warrior is more efficient with any speed bonuses rather than the Knight.
Not everybody aims to have the highest stats, usually just enough of what they need if they can help it so all this math isn’t important for those that try to raise their lower stats to balance themselves out.
(The opposite of min/maxing.)
Extra
On a side note, you mentioned the resurrected armor works best on a Knight. I personally think that it can help a Knight a lot, but I think the Paladin benefits more from it. (This is now a matter of opinion, and less factual.)
We can’t compare how effective the abilities are when wearing this armor because the abilities do different things and perform more effectively in different areas.
However, I can show how much a Paladin can benefit from the armor at only a cost of 5 wis.
Note: This is not including any mana regeneration as there are too many variables to use in what short time I have.
Without Armor
120 (Healed from Healing Duration)
112 (Heal from HP Bonus)
2.8 (Times the ability can be used)
649.6 (Health Healed Total)
With Armor
122.6
115
4.46
1059.696
This means that the armor allows the Paladin to heal ~410.096 more health than before, all at the cost of just seven defense.
This is why I would personally use a Ressurected on my Paladin if I had one.