We are not and do not need to do total overhauls. The other trees are perfectly fine.
G
But 80% of what you see are current policies. It's not a complete overhaul, just touching a policy or two in the other industrial policy trees.
EDIT. I'll highlight the changes:
1. Military bonuses, so they all can wage war in their own way. (
Aircraft / Naval /
Mercenaries)
2. Boost to some worked specialists, so Artistry is good for any of them. (Extra scientist/engineers /
less hungry specialists / extra great merchants)
3. Increased yields from some thematic terrain. (villages / Sea, coast / production improvements)
4. Something very thematic (golden ages / monopolies / trade routes)
5. Asociated buildings, so those get built faster (
Productive buildings / Military buildings / Commerce buildings)
6. Something exclusive (Observatories / Vassals and puppets control /
Unit purchasing)
Changes (remember, this is a brainstorming).
* Aircraft bonus is moved from Industrialism to Rationalism. As ElliotS pointed out, extra aircraft range for a expansionist civ is nothing, you can as well conquer a nearby city. Rationalism main use at fighting is getting to better units faster, but if you are playing for science, you are probably focusing on Public Schools and Research Labs, so you are going to arrive always late for the military units.
* Mercenaries to Industrialism. This could be anything that allowed better units by purchasing, be it Landsknetchs, be it removing XP penalty for purchases. Industrialism has more gold and can maintain a bigger army, but does not really have anything to help fighting.
* Food discount to specialists moved from Rationalism to Imperialism. Rationalism is a huge attractor for Artistry, and this policy is the main culprit. We are assuming that a Rationalist player is not going to expand, as the unhappiness would destroy the science bonus, and I'm fine with it. But we are also assuming that an Imperialist player is going hard on domination, always struggling with happiness. This does not need to be true. A player could simply benefit from having expanded hard in the past, or expanded through a puppet empire (slower but happier). Since an expansionist player that wishes to consolidate or is content with a puppet empire is able to work on specialists, why is not there any benefit to specialists?
* Bonus to productive buildings moved from Industrialism to Rationalism. If Rationalism loses the food bonus to specialists, then it can be replaced by a bonus for having production buildings. The only thing that Rationalism currently misses is a bonus in some buildings. Rationalism is the tree for scientist and engineers, isn't it?
That's it. Four changes. Not a complete overhaul.