Idea on improving the vikings lategame --> Change their late game castle tech

In my opinion the vikings have a pretty unique identity in that they are a powerful infantry and naval civ. They have a pretty decent eco bonus with an incredible naval bonus that allows them to be competitive in the lategame, while their infantry with a full tech tree boast some of the best FU infantry (we'll ignore the halbs).

However most viking players suffer in the late game due to the fact that they can't close out the game too well, especially in larger maps with teams. Their subpar siege in IMP, alongside a terrible cavalry means that on land they will get absolutely mauled, while their archer line is too mediocre to help support their infantry.

MY PROPOSITION is that we change the identity of the imperial castle tech from berserkgang to an ability that allows longboats to act as transport ships for infantry. Imagine that the viking player is transitioning into imp. His eco bonus has caught up and he has a powerful navy, but can contribute little to the fight outside of sending mass waves of infantry. Vikings are a raiding civilization, based on speed and shock potential. By making the longboats as a transport, they can quickly spread out their berserkers and infantry around the map, raiding and attacking enemy weak points while they are distracted by other attacks. This gives late game options for the vikings as powerful raiding civ that can disrupt trade, take down TC's and Villagers, while remaining a constant threat in the lategame and not be mauled by SO's in a straight up battle. I also think this is in line with actual historical vikings, who used longboats as speedy raid ships that allowed them to do hit and run against slower armies of the time.