Chichak has some Russian/Polish detailing but is pretty close to actual legionnaire helmet. Saracen lamellar armor for body isn't perfect, but it's red cloth with metal chestplate (should be segmented instead of tiny lamellar plates). Unless you use a custom banner on a board shield, long pavise is the closest shield you will get.
And you have to use throwing lances. Have a 1H sword on hand for backup. I used the nordic short war sword since it has a weighted pommel, but someone else said katzbalger looks close to a gladius.
It's not perfect, but that's what my legionnaire alt wears. Chichack, saracen lamellar, long pavise, throwing lance/nordic short war sword.