I prefer msi armor 570 8gb to mine because it has a good hashrate to mine a coin with Cryptonight algo like XMR or mine another coin like Decred.
MSI Armor = crap. Period. Cooling is shit, quality is shit. Avoid.
Also, you will not "mine another coin like Decred" because they are now ASIC territory and yield absolutely nothing on GPU anymore.
The last day you'd be able to mine ETH with a 4GB ram card is expected to be the 23rd of Feb 2021. ETH might or might not move to PoS before that.
Note that you'll still be able to mine everything else.
Now up to you to decide.
I was thinking about 8gb because of Cryptonight. But as you said Armor is low quality is what I was worried about.