What if you switch your light guns?
Like, putting that gun on the bottom.... wouldn't it work for engie top engie bottom?
Yes that works, as long as your gun still has arc. The bottom side gun doesn't aim directly forward like the top left gun does, so you have a difficult time running a Hades down there and a Mercury simply won't work. In these cases running double engineer on the top deck may very well be a good idea, since if you only had one engineer for the top deck and you put him on the Hades, he will never shoot the Hades, because he will be busy repairing the armor.
A thing I like is making my ship work without the top guns and so have one engineer on the top deck and one on the bottom, if the heavy gun gets destroyed too much / the enemy gets inside arming time, then the gunner can run the bottom side gun while the bottom engineer either buffs or rebuilds the bottom guns or can afford to spend his full attention to the engines and balloon.
An exception to that is when I make my gunner primarily use one of the top guns and keep the heavy gun for secondary use for either the gunner or the bottom engineer.
I never run double engineer on the top deck, because I don't see it solve any actual crew problems that the average one engi top and one engi bottom strategy introduces. If the armor is damaged, you need one engineer to fix it. If the balloon or the bottom engines are damaged, you need one engineer to fix it. If you both engineer have the Mallet/Spanner loadout so the less important gun engineer is able to repair any component all the time and the second engineer is only required in the emergancy when everything dies, you will then lose buff and you really want buff to speed up your huge, easy to hit ship. If both engineers are on top deck, then it is very likely that the balloon (!!!) will lose chem spray and die due to fire. That also means the gunner's gun is not chem sprayed (#Flare).
- An extra engineer up top so the usually important top left gun can fire while armor repairs are underway
There is something wrong with this sentence and the Metamidion is a prime example of why this sentence is wrong. The engineer is using the important gun, why is the engineer using the important gun, why not the gunner/gungineer? If your gunner/gungineer is not using the important gun, it isn't actually important. Of course, the Mortar for a Metamidion is just as important as the Gatling, but the Gatling is the actual important gun, because it is required to shoot constantly. If you have two guns that need to shoot constantly, like a Lumberjack/Hades Spire, then only one will actually shoot constantly and you have to decide which one will be it, the Lumberjack for the consistent balloon destruction or the Hades for the consistent armor destruction so your Flak has more chances to finish them?
The one problem most Spires have is that they for some reason think the engineer can somehow get away with shooting the important gun, but that's not how it works.
