Adding the Spanish archaic units to the Inca roster would do absolutely nothing to fix any of the Inca flaws. They already have archaic units that are mostly okay.
They do need some reform upgrades or cards but a double revolution goes too far. There should be an option to reform and gain European technology at least by age 4, and then maybe another option for a full revolution into an Inca flavoured Peru instead of age 5. That way staying as Inca or revolting would actually be a choice and not a necessity. If the reform options are not available until age 4, Inca needs good options for turtling and raiding to last until they can get their more advanced upgrades.
The reforms could do as follows:
-
Bolas Warriors get replaced by Bolas Riders. Bolas Riders would no longer be a native unit and could be part of the roster of a Mapuche civ. They would also be much easier to distinguish from Huaracas
-
Enable Light Cannons to be trained from the Stronghold. This would give them viable anti-artillery and let Huaracas be toned down into a more reasonable Abus/Grenadier unit.
-
Greatly increase archaic unit health and armour at the expense of speed. This could be a separate optional upgrade kind of like some of the advanced church upgrades.
Some of the other units are also far too multi-role and need to be split up into more dedicated roles.
-
Chincha Rafts should not be the entire navy. A Balsa Boat that takes on the Canoe role could free up the Chincha Raft to fill the stronger, more expensive ship roles.
-
Macemen should not be a siege unit, they should just be a strong infantry. Rams should be trainable at the Kallanka to fill the siege unit role instead. Rams would first need to not suck so some changes like this could be done:
Other ridiculous and gimmicky things like military garrisoning, converting priestesses, factory houses, invisible forts, and way too speedy pikemen could also be scrapped or reworked.