With the recent changes in BTC price, altcoin is getting weaker against BTC, so, this is a good time to pick and fill the bag. Another important part is, after BTC bullrun, once BTC get stable, altcoin follow the bullish trend.
Is it right decision to pick some more altcoin?
The history between bitcoin and altcoins movements is exactly the same as you said but we don't know what is going to happen this time. Will altcoins follow the bullish trend? In my opinion, yes this will happen but maybe after BTC hits new all time high.