The AA/AEC tech is dirty cheap adding another is hardly going to be "too much" it would still be less the T3 for soviet.
The point is to give UKF access to both a AI and AT vehicle that come earlier than medium tanks.
Valentine could get have good anti garrison gun and smoke rounds to help vs mgs.
And no units do not have to quite strong to be worth it, they need to bring something new to the table in this case it could be anti garrison utility.
I was confusing with the cost, AEC and bofor tech are 30 fuel totally so not that expensive, indeed.
So the next question is how will be the new valentine. What do you think about my proposal?