Does these advantages always a deciding factor of who wins? Too many other factors are important to know outcome.
Nice try, you almost got me. Almost.
Plated charger are OP, but how many of them you see right now? Pre-patch there was a rare situation to see more than one of them at the same time. Not all of the "plate charger riders" was owning just because of the horse, does Finn became a bad cav now?
Finn uses a charger currently, which is only a bit "better". Still a heavily OP horse.
But what you really want? Get back to summer? When horses was so underpowered that you rarely saw them at all.
To be honest, this was less of an problem than OP cavalry. So if I had to chose between horses from directly pre-patch and horses from this summer, I would choose the summer. But of course I would simply prefer balanced cav.
"Player + horse > player + nothing" that depends on many other factors, like their skill, equipment, level.
Let's get it straight, using the same approach:
"Player + bow\xbow > player + no shield"
"Player + shield > player + bow\xbow"
"Player + bow + horse> player + horse"
You are comparing apples to oranges here. So I marked them. (As my quote with "player" was meant to have the weapons included I marked the first players green, too.).
Horses belong into horse slots, weapons into weapon slots. The horse is always an ADDITIONAL item to the weapon slots, and I would say in most cases the horse, this additional item, is MORE important than 99% of all possible weapon slots items. A masterwork elegant poleaxe or something like that is the only thing being able to make up for... hmmm... a rouncey at the most.
So some kind of rock-paper-scissors WITHIN the same slot category (weapons) is always whished for, as it improves overall gameplay. But this doesn't work with classes which simply use an additional slot.
So cavalry stays OP, unless the additional use of a horse gets balanced by BOTH nerfed horse stats AND some secondary penalties using a horse, e.g. remarkably lower skills or poor other equipment.
Also, of course, I assumed the SAME player with same level and same skills, riding a horse or not. As I said: for the investment of a few skill points into riding skill you get higher mobility, flexibility, protection, knockdown + bump damage and increased speed bonus. Even pikes and throwing and other ranged weapons can't be counted as counterargument, as they are also a threat to footmen.
The only current disadvantage is higher upkeep, but especially for the cheaper horses you don't really feel it. A rouncey is a perfect horse for me, and I pay 370 gold upkeep or so for it. This has to be increased by 2000% or so.