Chem spray is the best provided the engineers chem before it's needed. If you are being flamed it is too late. In which case fire extinguisher is better.
But during prolonged exposure to fire fire extinguisher cannot cope. As this fire stacks will come back. So Basically if engineers forget to chem and you are under prolonged fire. Extinguish and then chem.
Mercury up front on a Junker is pretty cool. Makes the ship super tiny to hit whilst you have a gun pointed at them.
My favourite Junker builds are as follows though:
Front Artemis, Left side double hades, right side, carronade gattling.
Front Artemis, Bottom deck dual mine, top left Gatling, top right carronade.
Front Banshee, right carronade flamer, left side dual mine
But maaan Junker is such a versatile ship. You can design it to have each side for different jobs. It's awesome.
It's like having 2 pyramidions stuck to each side.
Without the nose.
Or the pyramidion.
That's what i think anyways.
Not optimal how? We regularly go 5-0 with it. Flaks not only assist gats in armor damage, but are great for hull damageas well. I can show you how effective it is tontight if you'd like.
It isn't optimal as the flak has an arming time. Which means that the gat is often out of range. Mortar is a better pairing.
Provided you want to be a Metamidion Scrub.