This is a hypothetical imagination for fun, so don’t need to take it too seriously.
Just present this thread as a joke if don’t like it.
The UU changed to Navigator (or named to Explorer) to replace the long criticized Organ Gun.
With a skin based on the AoE3 Explorer or mercenary Cannoneer, the Navigator is also a powerful gunpowder unit to maintain the identity as the gunpowder civ and the popular FC UU strategy.
It also reflects the activities of the Portuguese in Africa and Asia, just like the Spanish Conquistador.
To reduce changes, most of the Navigator’s stats could be similar to the Organ Gun’s, such as wide LoS, high attack, and slow speed. The Navigator’s projectiles could have a blast radius to mimic the effect of Organ Gun’s multiple projectiles.
Due to the change from a siege weapon to a Hand-Cannoneer-like unit, it might have lower HP and higher armor than the Organ Gun, in order to maintain the weakness against the Mangonel as much as possible and maintain the quality against other units.
Castle UT get renamed to “Navigation School” and also provides armor or anything else to the Navigators.
I think UTs that only serve water tend not to be good UTs. Either it becomes a civ bonus or a team bonus, or it benefits land as well.
Missionary can be trained.
The Missionary would no longer be an UU, but a kind of regional unit for Spanish and Portuguese.
Of course, the Missionary itself can get some improvements, such as able to collect Relics (the speed when carrying is the same as Monks) and so on.
Caravel fires cannonballs.
This is according to my another thread.
What if Caravel fires cannonballs?
Lose Heavy CA and introduce Jinete/Genitour as the new second UU in the Castle Age.
Jinete is a kind of stronger mounted skirmisher unit that cost gold and have no minimum range. May have elite upgrades in the Imperial Age.
Its button could be located where the original Heavy CA upgrade is, and its elite upgrade button is located where the Parthian Tactics is.
The current Berber Genitour could be renamed to the more accurate and decent “Zenata Rider”.
This doesn’t make their Archer line competitive, but makes their early game strategy more flexible.
Bonus of the faster cannonballs of Cannon Galleon changed to free Elite Cannon Galleon upgrade.
This is totally my personal choice. I can’t always get used to the cannonballs of Spanish Cannon Galleon that are much faster than others, and I also think the free upgrade will be more practical.