A green, yellowtail or banjar red will not show that intense dark colored back especially when juvenile. As for the horse shoe patterns. On green, yellowtail and banjar the horse shoe patterns are broken especially around the back area and end up looking like oval shape spots close to the anal fin. It becomes more higher in contrast as it grows. Compare to RTG, SR and XB they also show the horse shoe shape pattern when juvenile but they are not broken and it look like a full letter "C".
I never seen a RTGx Green before so I cannot say anything about that. I also won't say it's a banjar or yellow tail as I got both those fish and juvenile banjar or yellow tail does not look like that. Banjar red and yellow tail does not have a brown or grey dorsal fin and the back does not show a shaded dark color.
I'm leaning toward RTG but can't say 100% since the fish is still young. Best to update us when it's around 12-14".