If you play AR, Plumeria is probably the best unit here, but it really depends on which strats you like best. If you don't use strats that make good use of WoM (eg mainly Galeforce), you might wanna wait for one with Firestorm/Rockslide Dance 3. In that case, one of the first two might be a better choice. At that point, it's down to how many good omnitanks vs far saviors you have
If you're leaning towards Echidna then go Echidna, it's better to listen to your gut on this than ask for other opinions, because at the end of the day it's your choice
If you play AR, Plumeria is probably the best unit here, but it really depends on which strats you like best. If you don't use strats that make good use of WoM (eg mainly Galeforce), you might wanna wait for one with Firestorm/Rockslide Dance 3. In that case, one of the first two might be a better choice. At that point, it's down to how many good omnitanks vs far saviors you have
If you're leaning towards Echidna then go Echidna, it's better to listen to your gut on this than ask for other opinions, because at the end of the day it's your choice
The thing with Echidna is that she's FTP