Triumph only increases the damage of tusk and not the arrow on mercenary tower elephants

The triumph ability on the Byzantine Imperial Hippodrome works on mercenary tower elephants, but the damage increase only works on the melee tusk attack, not the ranged arrow/crossbow.

Might be by design as elephant is composed of 2 parts, elephant and mounting.
Elephant part is cavalry while mounting part isn’t (war = spear ; tower = archer).

Let see how dev reply.