Here is one in 19:
But I consider it a bit stronger if you take you a bit more time. The prob with the 19 min is the one-time powerspike but no followup other than just going full donjon rush. This makes you predicrable. Of course if your opponent isnt prepared in time, it’s too late. But if he knows he can go for the counters, which is walling + siege or elephants if he has a strong ele civ.
Here’s why: The first crusade total ressource spike in military is nice, if you give the castle age serjeants a value of about 80 res/unit you get about a value of 4800 (necessary add. upgrades + buildings included) in long swordsman from it. The Investment done is about 3400 res though, so you are indeed 1400 military value ahead, which is indeed much more than any good eco civ can pull of. But the time you spent walking over + the defences of your opponent can mitigate some of this advantage. The Advantage is not that much it guarantees you a win. It’s a very strong powerspike but no unbeatable powerspike, especially in arena, which is way easier to defend.
So, the Idea is to take you one or two minutes more time, the powerspike itself is the same, but you have more options to continue. Because you should already have build some farms you could just knock on the enemy door and booming behind because you already placed 5 TCs on the most important ressources, so your eco is protected while you threaten a donjon rush and get the map control. You bust your powerspike because the tcs you placed to get the crusade rolling now become booming tcs “for free”.
The other option is that you comit hard to the donjon rush then. Because you took yourself a bit more time and placed some farms and placed your tcs well organized and not too close to another you have a healthy eco behind that donjon rush and use the ability of the serjeants to build them as “free builders”.
And of course you can also go half boom half donjon rush.
Bacause your opponent loses all map control once you researched first crusade he has no clue what you are doing and has to decide preemtively what strat he will go for to answer this. As you will see this due to your map control you just adjust your strategy that way you either use the first crusade just as a distraction if he heavily commits to counter the donjon rush or donjon rush him if he gets too greedy.
With this strat in mind, there is almost no counter to the fc first crusade strat other than try to punish the fc, which is indeed impossible on maps like arena.
I also wouldn’t go for a castle drop or something like this. The first crusade gives you the utility to get an insanely strong offensive powerspike from a pure defensive play. This you should utilize as much as you can. Because the serjeants + donjon rush give so much offensive value you don’t need a castle drop. It just gives your opponent the opportunity to snipe your forwarded vills. But the advantage of the donjon rush is, that you don’t need to bring any villagers forward to pull it off, so making a castle drop takes away one of the advantages of the first crusade + serjeants.
I haven’t made a buildorder or something like this yet, because I think in its current state its just not balanced. The donjon rush is in it’s current state impossible to balance until they take away pe the arrows from the donjons. It’s a even more utilized version of the tower rush which is impossible to balance either, so how the donjon rush can be?
And the first crusade needs to be adjusted. I’d like to see that you get serjeants for each donjon you already build, so it gets utility, either offensively or defensevely. But other than it’s state atm you need to have already invested in and commited to the donjons already. This would balance it out and make the uncounterable outplay I described above impossible, because the oponnent will know what he is against.