there's too much wrong with this to go correcting it as well.... well actually the same amount of wrong, which is one statement. so i suppose ill take a stab at it.
Wait, how can a statement be just as wrong as a statement that says it's wrong?
But I guess I should elaborate a bit since no one else has. There are two problems with Bushface's analysis. First, he compares LK and Maces in a vacuum, ignoring the earlier, easier Longbows (which automatically get CG 1 and Drill 1), city defense, City Raider promos, the inevitable siege which LKs are very weak against, and, more importantly, the LK's best era-appropriate counter (crossbows).
Second, the math is somewhat off.
"So Mace attacks LK; Mace str.8, LK 6 +100% -50% from the Mace = str. 6 +50% = 9.
Or LK attacks Mace: LK str.6, Mace 8 + 50% -100% from the LK = str. 8 -50% = 4."
The Maces attacking LKs in a vacuum have an 8:9 ratio, like mentioned above. However, LKs attacking maces have a 6:5.33 ratio, not 6:4. That's a really significant difference. Combat odds are 30.8% and 69.4% respectively for anyone who's counting.
Then, you have to factor in promos. Assuming the defending LK has the same number of promos as the attacking Mace (unlikely), and assuming the attacker was competent enough to reduce city defenses to 0% either via spy or siege, you'd get this:
Level 0: Mace : LK = 8 : 9 (30.8%)
Level 1: CR I Mace : C I LK = 8 : 8.4 (34.8%)
Level 2: CR II Mace : C I Shock LK = 8 : 8.4 (34.8%)
Level 3: CR III Mace : C II Shock LK = 8 : 7.2 (68.7%)
Level 4: CR III C I Mace : C III Shock LK = 8.8 : 7.8 (69.7%)
Level 5: CR III C I Shock Mace : C IV Shock LK = 8.8 : 6.9 (76.1%)
Level 6: CR III C II Shock Mace : C V Shock LK = 9.6 : 7.5 (76.3%)
Level 7: CR III C III Shock Mace : C VI Shock LK = 10.4 : 9 (71.0 %)
The difference is much less pronounced for LKs attacking the stack (which we will assume has a Shock/Combat Mace for defense)
Level 0: LK : Mace = 6 : 5.33 (69.4%)
Level 4: Shock C III LK : Shock C III Mace = 7.8 : 6.66 (71.7%)
Level 6: Shock C V LK : Shock C V Mace = 9 : 8 (69.4%)
Level 7: Shock C VI LK : Shock C VI Mace = 10.5 : 10 (65.5%)
On top of that, this assumes parity between the mace and LK's level, which, in my experience, is unlikely given that defenders don't tend to last long compared to attackers. This also assumes no crossbows, which, if you have iron, is sheer incompetence if going up against LKs. If you bring them, the situation would be as follows:
Level 0: XB : LK = 6 : 4 (92.7%)
Level 1: C I XB : C I LK = 6.6 : 4.28 (93.4%)
Level 2: C I Shock XB : C I Cover LK = 6.6 : 4.28 (93.4%)
Level 3: C II Shock XB : C II Cover LK = 7.2 : 4.61 (93.7%)
etc.
Of course, if there are both LKs and Longbows in the stack, the crossbows are pretty certain to attack the latter. But which would the maces attack? To answer that, let's look at that same maceman attack assuming the HRE was defending with Longbows, not LKs.
Level 0: Mace : CG I Drill I LB (due to protective) = 8 : 8.7 (24.3%)
Longbow > LK
Level 1: CR I Mace : CG II Drill I LB = 8 : 9 (22.5%)
Longbow > LK
Level 2: CR II Mace : CG III Drill I LB = 8 : 9.9 (18.0%)
Longbow > LK
Level 3: CR III Mace : CG III Drill I Shock LB = 8 : 9.6 (19.4%)
Longbow > LK
Level 4: CR III C I Mace : CG III Drill II Shock LB = 8.8 : 9.6 (19.0%) (notice the first strike chances skew the relationship between power ratio and %chance)
Longbow > LK
Level 5: CR III C I Cover Mace : CG III Drill II C I Shock LB = 9.6 : 10.2 (20.1%)
Longbow > LK
Level 6: CR III C II Cover Mace : CG III Drill II C II Shock LB = 10.4 : 10.8 (21.2%)
Longbow > LK
Level 7: CR III C III Cover Mace : CG III Drill II C III Shock LB = 11.2 : 11.4 (22.3%)
Longbow > LK
This advantage is exacerbated even further if the town is on a hill, since the LBs get 2 25% bonuses in that case and the LKs only get 1 25% bonus. This also doesn't even take into account that LKs require 20% more hammers to build.
Of course, if the stack were out in the open, the Longbow would lose a huge chunk of its potency, as would the Maces. In that case, you would attack with Crossbows instead and save the maces for city raiding. Level 0 Crossbows attacking a stack consisting of both Level 0 LKs and LBs in the open would have a 92.7% chance against the LKs and a 46.6% chance against the LBs, even taking into account the Drill I level 0 HRE LBs start with. A level 0 Mace attacking the same stack would have a 30.8% chance against the LK and a 70.8% chance against the LB, so even though a mixed stack of both LKs and LBs has some decent punch, it's nothing spectacular if the player has 1) iron and 2) competence.
So based on this, we can pretty much say that the LK is a poor performer. For city defense, Longbows beat LKs against everything but cavalry (which is the case with normal pikes, too) and Maces (which, if the opposing army is competent, they won't leave exposed). I guess against really horsehockey players, or if you suck at math, LKs could seem good. But to answer the topic question of "Would you go to war against the Holy Roman Landsknecht?" I can safely say that since an army heavy on LKs will be worse than one without them, yes, I would.