Notice none of these show mixing subwoofer impedance as the subs won’t get even power.
But to more specifically answer your question, if you were to wire the subs in PARALLEL, you’d get a 1.33 ohm impedance, which will destroy your amp.
If you wire both subs in series, the impedance goes up to 6 ohms and won’t get as much power from your amp. So this means your amp won’t be near putting out rated power.
As everyone is telling you, keep the 2 ohm sub on the amp so you’ll get maximum rated power from your amp. By the way, I couldn’t tell from your contradictory posts, which was actually the 2 ohm sub.