I just builded full archer rain of death on upon them. they (Jugs) die easier, but without full army of archer, they (Jugs) are very deadly, but every should had a weakness...Juggerauts is strong in melee, try stay out of Juggerauts's melee range if you can, force on them first if no enemie deady mage, had lot of archer if that faction depend war on you and do building a Juggerauts, but thing is that Juggerauts do great boom Power rating, make more likeky depend war on you.... Of course, I once fight those 5 of Juggerauts in city....I had 5 to 6 longbow archer with 2 to 3 hero who had a archer as well...I do and did taken a faction "archer" bouns, replace normal bow, far better faster, had 75% overcome densce, ect...
Edit: I don't know I do not builded Jugs myself, as I see A.I build lot of Jugs much faster than my archer troop, it's seem taken longer for me to get archer up than Jugs, if I want best and get more number...having a deadly archer is too long time reseached with max number of troop with best bow with well choice trait...they are deady, but on other hand, I'm not sure what to do in early game if that case you can't reseach all the way to archer, best archer in end of tech tree...same for number of troop in civil reseach as well as they are end of tech tree..
if You knew those faction are building Jugs, you might want drop your plan and go for archer and unlock number of troop number as soon as you can...
Oh, if you don't had a "archer" trail and normal bow cost metal, and not had metal, normal bow taken much longer and lost a turn, gave Jugs chance to kill your "normal" archer...I guess you screwed, you had to find other way...I did try cast fireball or fire dart, but they don't do a job, they don't do much damage and taken 2 turn to recast and had a mana cost lot..at early to middle of game...