I'm afraid to get a Green Cheek Conure after seeing things like this

I would love to get a GCC next year (have wanted a GCC for a really long time... I have never owned one before) but am seriously concerned to get one! Rascal (my tiel) LOVES other birds... you should see him when he's near other birds... he immediately cheers up and starts singing to them (it is so obvious).... but after I googled "green cheek conure killed cockatiel" I am having doubts!
I saw this following video on youtube and the owner of that GCC is CRAZY to stand there and allow his GCC to attack his tiel like that. It's a disaster waiting to happen and if I ever saw my GCC conure that aggressive towards my tiel I would have to re-home the GCC. Is that very COMMON with GCC? I mean... for those who own GCC and a tiel... does your GCC attack your tiel like shown in this video:
https://youtu.be/NgaQWViW7Mk (I know the tiel in this video is a moron who should get a clue LOL... but still). I wouldn't keep the tiel and GCC in same cage of course... but I'm very worried what if GCC suddenly decides to bite my tiel in the throat, face or feet. My tiel won't stand a chance?
I was so excited to eventually get a baby GCC but after I spent time on google now I'm scared to
