http://screenrant.com/arrowverse-crossover-tom-welling-superman-earth-x/

Smallville’s Superman, Tom Welling, would be happy to appear in the Arrowverse – so could he appear as the new Clark Kent of Earth-X?

Supergirl Just Teased a Direct Connection to Smallville’s Continuity (https://www.cbr.com/supergirl-smallville-connection/?utm_source=CBR-TW&utm_medium=Social-Distribution&utm_campaign=CBR-TW&view=list)