Upgrade tree rework

I don't like 4. It might be too much for one idea.
I'll upvote it, if it remains on the only topic of upgrading troops.

Yeap, agree, have removed it, if someone curious the 4th was: 

disbanded units shall give you some bonuses. I have created thread already about domestic politics, where proposed the idea of nations in the game, so if it was implied, then disbanded units could provide citizens with some additional bonus for industry or food

Upvoted.

EsoulBoy wrote:
Firstly, spearmen can’t upgrade into anything (except if you pick the Greek or Persians), so if you had to fight against horses in first era,  then the only nations you can peek are those 2, either you have to build all new units and keep spearmen somewhere far from battlefront.

Same issue with the archers in the 2nd Era

Not sure there is a better thread for odd upgrade paths but I noticed one for Mauryan EU. The Saṃnāhya apparently upgrades into the crossbowmen which gives them a glorious +1 combat strength, while losing them the elephant platform (i.e. no melee penalty). It just seems counter-intuitive that this unit wouldn't upgrade to the Dhanvī-gaja (Khmer EU) which is basically the same thing, a ranged elephant unit. Maybe it's because that would make the progression too powerful? But wouldn't there be a better way to deal with that.

Might also be useful to include some form of tooltip what the next upgrade for a unit would be, rather than just saying nothing is available atm.

Not sure if there are more examples like this where the upgrade progression seems unintuitive.