I have a similar strat, though I don’t try to get the steeds for every character. I will look at something from a role-playing perspective. My male elf wouldn’t be caught dead on a warsteed with a basket of sunflowers perched on its rump. My female elf likes flowers, but wants something more elegant. My hobbit lass? perfect for her!
I’ve also used the festivals to take advantage of getting a goat very early. It’s a bummer to get to Moria and have only that starter goat (Mirv, I’m looking at YOU!) so I try to make an early investment. I was disappointed to get my new beorning to the festival and find she couldn’t hunt eggs or mushrooms at level 6! Since she won’t be in Moria this year (I am pretty sure), I will work with her in a later festival.
Also, it’s always very, very important to check out which steeds have warsteed apparel equivalents. I used to buy entire sets, but now I tend to pick up individual pieces (one festival, for instance, I bartered only for braided tails).