The current movement of altcoins will exceed Q4 2017. We can see based on the current Bitcoin price movement. If the Bitcoin movement has started, then Altcoins will join in, although it is not currently visible for all Altcoins. Faster to follow Bitcoin's movement are Ethereum and Binance.
It is better to focus on the top ten or even just top five altcoins if you want to hold for the long run and sell at higher prices. Rest of the altcoins simply follow the bitcoin trend a bit late but not enough to reach all-time-highs. So bagholders of shitcoins need to stop bagholding and dump them at the next bullrun to exit.
Although I cant say if they will exceed 2017, I can say for sure that if they cross they will have a bloodbath selling pressure. Because some people have been patient after buying at the highs back in 2017.
The easier and safer thing to do when the market is rising is wait for the prices to come down, or sell if you already own that asset. So sell bitcoin and hold the fiat for bitcoin to come back down. Dont diverse into altcoins just because their prices might be low and you feel they are going to go up - they will not.