AI To Ignore Base And Target Heroes Only?

[Run3m4st3R]

Hey everyone,
I'm trying to build a mini-game where the player uses a hero only and has to survive as long as possible against AI players who roam with armies as they would in a normal player versus AI match. I can't seem to get this right, and I'm not too well versed in the AI editor.
Is there a way to get the AI to behave exactly as it would normally, but to target my heroes exclusively?
Answers appreciated

 

[Warseeker]

• AI - Ignore "unit" garde position

Or "Units - Order "picked unit" to attack "that hero"