We can solve the LTE issue by integrating the stallions.As in, it doesn't affect LTE, so this is half a secondary action's value per turn here.
I feel that adding a True City, taking the hit of -2 Econ and -2 LTE, is the bigger problem here. We do not suffer from low econ because it's the cheapest stat to generate, but we DO suffer significantly from lowering LTE, which has always been the actual problem with maintaining enough Economy for use. With the switch to Wealth, we don't really pend much Economy anymore, and can obtain sufficient with even one Main Expand a turn fairly often
We are currently at 17 LTE, and when we got a new province this turn it have us +8 LTE, so that is 25 LTE to play with. Even if we lose 2-4 LTE for the city (not sure which it is; does transfering Econ get us econ expansion back? I.e. is the cost -2 Econ, -2LTE, or -2 Econ, -4LTE?), that still leaves us with more than 20, and without climate damage we aren't going to be dropping much.
As far as not depending on economy too much, you aren't wrong - but having enough econ to transform into wealth is valuable. We want to get to that point if we can, and once we do +1 econ will be as good as +1 wealth.