Your analysis is good but based on my experienced and analysis on ethereum it's still follow on the move of bitcoin in other words if bitcoin will go down right now ethereum will also follow this is the power of bitcoin, but yet its a good move for ethereum to hold the $180+ level.
This reminds me of first quarter of 2018 wherein the downfall of bitcoin started early but ETH was at it's all time best value and survived there for approximately 3 months then ETH started to fall as well. I believe that the growth of all the altcoins are related to bitcoin's growth. I think it will take ages for altcoins to perform individually.