Attack boost ability of Einherjar, Arkantos and Chinese General works only on handattacks. It doesn’t affect ranged attacks: Bogsveiger, Throwing Axeman, Troll, Fire Giant, Chu Ko Nu, Mounted Archer, Fire Lance, their UI shows fake yellow values.
Note: it also doesn’t affect Fenris Wolf and special attacks, but it might be intentional. Fenris Wolf’s UI doesn’t show fake attack value.
Repro: test mod with extremely high values (+10000% boost rate), compare ranged units to units with handattack. Huskarl destroys a Temple immediately, Throwing Axeman does regular damage. Throwing Axeman is near to the Einherjar of course.