I don't think equal techs for every civ is necessary. We can also just combine some techs for groups of civs:
- construction available to Gondor and the first or first two are also available to Numenor
- Shaft mining/expert mining for both Khazad races, but only mithril smithing for Longbeards (maybe something else for the others or not)
- Rohirrim & Haradrim & Easterlings get all the first special horse tech (Horse mastery maybe) and then the Rohirrim receive 2 more horse related techs, the Haradrim only get this one and a Mumakil one and a piracy one and the easterlings only get the first one and the second one for the chariots maybe. Chariots can also be done in multiple units (chariot with one horse, better version with two horses called war chariot or something like that).
- Maybe combine some of the techs for ships for Numenor and Teleri (but providing different UUs).
The idea of doing it like this is that we limit the amount of techs we add because we cluster it to groups of civs, while still making them feel unique, by combining them or even having some special ones for really one civ. I think really trying to give a equal number to all is not neccessary if we balance this properly with how long it takes to research them and where they are in the tech tree and what they actually give as benefits.