Only sumpters carry goods?

[Bjarky]

first of all, always more horses than troops (no matter what), but if the crates exceed the troop number, then u need more horses than crates.

[dodnet]

I just don't get why you need one more horse... is the army lead by the horse or what?

[Bjarky]

as vovka already pointed out, there may be a chadzlandian donkey in between, yes   

[Rhekimos]

I just don't get why you need one more horse... is the army lead by the horse or what?

The hero also needs a horse. All 100 troops being on horseback isn't enough.

[dodnet]

The hero also needs a horse. All 100 troops being on horseback isn't enough.

Heros can run for weeks without resting! Haven't you seen Lord of the Rings? 

[Bloody_Santa_Claus]

20 crates. 1 crate = 6 goods, so 100 troops + 20 crates (= 120 goods) -> 220 (or 221) horsies needed. No idea if it's correct but seems stupid. I need 1 horse to carry 1 ale? 

these numbers doesnt seems legit,  1 horse can carry 1 crate, so 121 horses should be enough to get best speed. There are some rules:
44.55 speed with more horses than troops, and equipment worn directly, without any crates
36,8 if you have more horses than crates and troops
32.5 with slow horses,
27.6 if you have more slow horses than crates and troops
25 to 22.5 with equipment worn directly (depends on the troops and weight of the equip you wear), without any crates
22 with more horses than crates, but more troops
18.75 to 10 if you have troops carrying crates.