If not, are they using those clusters even if they are not certified for those profiles?
Just being zigbee isn’t enough. But if they are certified for one of those two profiles, they probably will already work with SmartThings using one of the existing device type handlers.
If they are not using the ZLL or ZHA profile, they might not be able to work with SmartThings at all.
See the following ( this is a clickable link)
If the lights are commercially available, we’ll need the brand and model number.