I'm not seeing how we can have cruisers before you can have ironclads. If anything I'd expect steam paddlewheel hybrid frigates before being able to build ironclads with cruisers being the next logical vessel.
Sea-going Ironclads, as opposed to 'floating batteries', start appearing in the 1860s in France, UK and USA. The distinction between 'Battle' ironclads and 'cruiser' ironclads starts showing up in the 1870s, or 10 - 15 years later - a short time in Civ terms, but real. Earlier, the addition of steam power to sailing warships had started in the 1840s, and before the Civil War the US Navy had an entire class of ships called 'Steam Frigates' that were conventional sail-era frigates but with steam engines and screw propellors added.
To cover everything, we'd need a 'quick and cheap' Upgrade from Frigate to Steam Frigate, followed by the Ironclad, followed closely by the Cruiser, followed (about 30 years later historically) by the Battleship.
Again, per my above comments regarding railroads, I think steam needs to be more forward on the tech tree. Also, given how factories (as we know them) were more engine powered and thus needed steam or electricity, having factories early doesn't make sense unless you make an early form of factory which requires a waterwheel which certainly makes historical sense given how that was the big limiting factor on factories was the need for water power. Indeed prior to steam, I'd say textile mills, cloth mills and the like would need a waterwheel prerequisite which would drop away after steam.
Agree. The first 'cotton' (mills) factories started in the 1740s in England, powered by water. It wasn't until the perfection of the stationary steam engine in the 1770s that the first steam-powered factories were built, the first being also in England in 1785. The big cloth mills in New England in the USA were almost all originally built on rivers to take advantage of water power and only later converted to steam.
So, you can have your first Factories about 40 - 50 years before Steam, but there has to be a river where the factory is built.
The technology of the overshot, geared waterwheel, though, is much, much earlier: the Romans were building multi-wheel-driven flour mills in the 1st and 2nd century CE and wheels driving everything from saws to hammers (wood and metal working) to flour mills were in use all over Europe by the late middle ages.
For the Civ-V Eras, Waterwheel/Mill should come late in the Classical Era, Steam at the very end of the Enlightenment, with the building of the first steam-powered factories sending you right into the Industrial Era, which is where the ironclads, cruisers, and railroads go, since they all require the Industrial application of wrought iron/steel technology that pretty much defines Industrial.