LVL 5 NPC Ballastia only

[Jonna]

http://battle3.evony.com/default.htm...41f20038dc.xml

i lost 474 ballistas at a level 5 NPC.. Sending 4000 of em.. i cant seem to figure this out.. i sent a hero level 30 with 101 in attack

If im gona have huge losses like this, im gone stop attacking NPC level 5 and up..

last weekend i attacked with 550 ballistas, and didnt loose any troops.. but on tiesday i hit with 550 first attack and lost ALL.. tried again with 680 and lost them also.. Wednesday i tried again, this time with 2002 ballistas.. LOST EM ALL.. And now loosing 474.. WHAT am i doing wrong here??

I can take level 4 with 400 ballistas without losses.. figure this who ever can.. because i cant..

http://battle3.evony.com/default.htm...f6822c55ed.xml

My research is as follows:

military tradition level 10
iron working level 9
horseback riding level 9
archery level 8
medicine level 9
engineering level 7

can anyone tell me what i am doing wrong?