Rail transport

Perhaps we could try transportation between guild member with railway system with train animation

1x1 size for rail track, when rail track meets river/sea, replace with a bridge connect between land.
2x2 size for train station (Qty:1) Only accessible after build Guildhall.

Its purpose is (A) allow guild member to drop combat buff (e.g ballista, horseshoes) to destination
(B) drop/pull any troops (max limit is 1000) for reinforcement if user urgently needed.

Transport duration increase depend on amount of buff/troops send to user.

this is just trading with extra steps, let alone a ton of dev and art work for a feature that exists (trade) or can be done in-adventure already sans trading (buff kills)