Roman Soldier Mount Effect

[Aulus Caecina Severus]

Example:
At Carrhae, the Parthian Kataphracts were covered in silk drapings and slowly walked up to the testudoed legionaires(or whatever formation you want to call it, probably had pilum sticking out from between the shields). At that point they threw them off thinking the legionaires would be surprised at the proximity of a ton of cataphracts. Despite the advantage of surprise, the cataphracts didn't attack because the legionaires didn't budge. The cataphracts withdrew until the missiles, heat, and lack of water broke down the legionaires enough that the Cataphracts broke them with a charge several hours later.

There are too many people who say that Carrae is proof of how the cataphract can beat the cohorts.
But from what I read this did not happen in a fight at par.
This is because the roman cohorts were totally exhausted and hungry, worn by several ambushes and never attacking from the front in the open field.
Personally i agree with EDU development of Eb team: the choice of giving high value to spear due to reduce light_spear deficit against infantry.
But this is also a problem because all infantry(except ap infantry) are so weak in melee against cavalry.

For example:
respectively value / lethality of edu / lethality of animations /bonus with cav-inf

attak of sword 11 / 0.13 / 0.51 / 0 - 0
attack of spear 15 / 0.13 / 0.41 / +8 - -4

Then spear become 23 against cavalry and become 11 against infantry: this is right in my mind.
But infantry just 11 against cavalry: too little value.
The solution would provide a bonus of +4 to infantry(against cavalry).
But some types of infantry is better against cavalry (depends from type of weapon), then we can give a +6 or +8 bonus against cavalry.
This is what i ve done in my unofficial EDU: https://forums.totalwar.org/vb/showthread.php?t=119572

[Parallel Pain]

Iunno. I remember in both my Saka and Saba VH/VH campaigns of luring Ptolemy/Seleucid/Bactrian General/Cataphracts to charge a unit of foot archer or skirmisher and then proceeded to swarm those heavy cavalry with more foot archers and skirmishers in melee, who promptly chewed up these heavy cavalry in no time. But even without swarming these completely no armor foot sloggers last pretty long in melee as long as the impact from the charge isn't too great.

And this was VH/VH

It seems to me that cavalry of any type is pretty weak in melee with infantry