Strut rods

I’ve seen it before when the big round bushings wear out.... but check the lower control arm bushings. They are likely shot also. As for your question:
If you mig up and rebuild the metal then grind them back to diameter, it will be weak. Not from the welding (okay you need to follow Proper welding procedures). The weakness comes from the grinding. Those were hot drawn thru die so grinding marks “could possibly” be a weak point.
“Could”
Joe