I have raised bed container gardens and I have ants moving in. Doing research I find one article that says they are beneficial and pose no threat and the next article says the spread disease down to the root.

If they need to eradicated how do I do it without running off the good guys like the lady bugs?

I really don't think that you can. Ants in general don't cause much in the way of damage in my experience.
In a world where we have thousands of insects per square meter and perhaps millions in a yard, there is no practical way to eliminate them.
And to be honest, I don't think that that is a good idea.

But if there are harmful insects such as squash vine borers destroying my zucchini plants then I would want to stop them.
But if insects appear here and there, I would be inclined to leave them alone. Insects are part of "the joys of gardening"!

Middle TN, that sounds like fire ant country. Fire ants can put a farmer out of business, or wish he was out of business. I have been dealing with them ever since they were imported.

In the garden I usually put laundry soap on mounds and wet it in thoroughly. By the end of the day two thirds of the ants will be dead. Within a week almost every one of them will be gone. I am not aware of any harmful effects the soap has in my garden.

I use it around my fig trees too. Fire ants can kill plants and small trees that have sweet sap. They cut into the roots and have a juice party. A few days ago I found two pea vines dying. Fire ants had eaten the "bark" off their stems close to the ground and were guzzling the vines' juice. So long to those devils. A dose of soap saved the other vines.

what they said

Ants may "move in" if they have a "new resource"

Sometimes, but not always ...ants may show up if there are aphids around ....aphids and ants have a unique relationship ...
the aphids feed off plants - then secrete "honeydew" that the ants "harvest" and take back to their mounds ....In turn,
the ants protect the aphids from predators .....when ants are around aphids, they are unusually docile

look for aphids around new tender vegetation, at crotches of stems & under, and in folds of younger leaves ...where there is one, there is probably a colony ....
aphids are tiny - the size of a pin head, up to 1/4" ....and pear shape
they are usually bright yellow, but can be: black, brown, green, orange or red ... there may be more than one color in colonies

there are over 1,300 species of aphids - and some have the ability of flight during their life-cycle

Control the aphids and you control the ants .....

A jet spray from a hose nozzle will wash-off aphids ...but that could also damage tender vegetation

another option is using Insecticidal Soap - make certain one of the ingredients is: *fatty acids* ...available already mixed at garden centers in Big Box stores or
make your own homemade version .....there are many recipes for Insecticidal Soap

spray insecticidal soap, let dry, then wash off with water - once dry, insecticidal soap yield no benefits and may harm plant tissues if left on during a hot day (upper 80°+)