Primary vote is redesign our tank
Redesign is obviously revision, not design action.
If you want to design a tank... design another tank. Preferably light and cheap with 2 oil engine
We must not lose the Plains
And we will not lose when we will revise our tank
We really can't afford to fail in getting our tank Expensive. If our Revision rolls are as bad they were last time, we'll lose the Plains and possibly the war. As for redesign vs revision, a redesign is more powerful and more likely to succeed with bigger changes than a revision. While we're redesigning the tank, we could give it an electric turret or even optics so it can take out enemy tanks from a larger distance.
We cannot rely on a Light tank. Light-armoured vehicles can be taken out by .60 caliber weapons which the enemy fields in abundance. We need a proper MBT to challenge the enemy's.
Holding on to the Plains is absolute highest priority. A redesign of our current tank is significantly less risky than developing mobile artillery or a light tank. Unlike a boat, it'll actually be useful. First of all, we might not be able to use boats in the Plains. Secondly, boats would be used for support while we need something to bulk up the centre.
Remember, redesigning will not only increase the chance of getting a decent engine, it'll enable us to add extras like electric turrets and optics.
Glory to Arstotzka.