It is still a shock...
When my daughter and her husband contemplated a barrier such as that, she was against it and her husband was for it...until she made him wear the collar and zapped him a few times...case closed & a secure fence was installed!
Sounds like you are out in a rural area? If so, I would still opt for a Harness as the threat of wildlife entering your property would still be a threat not worth taking. I live in a residential neighborhood but, it is on the outskirts of a rural area...thus, we have the threat of visiting "coyotes" and lurking "hawks" always on the hunt.
It's just not a chance I would take with my Yorkies.