Btw because i didnt mentioned yet one very important thing why I also compare Serjants to Champs:
They are very equal Combat wise:
Champ does 10 Dmg per Hit to Elite Serjant → 75 Hp → Kills it in 8 Hits
Elite Serjant does 11 Dmg per Hit to Champion → 70 HP → Kills it in 7 Hits.
Serjant cost 75% more Gold and 15 more Food then Champs and cant be mass produced out of Barracks → Champs are a very good counter to Serjant
(Knight line is also very good very Serjant because of its high armor vs their low Attack as long as there arent to many Halbs)