If you are really able to limit your exposure to shitcoins to 20% or less the size of your bitcoin investment (or the amount that you put into bitcoin) without cheating, the that is likely going to save you from losing too much, yet there are not too many folks who can limit their shitcoin exposure, and I frequently recommend no more than 10% exposure to shitcoins, yet if you can be strict with yourself in regards to the 20%, then it could be reasonable, even though it is a higher percentage than what I would recommend. I personally have less than 1% of the size of my bitcoin investment in shitcoins.
Exposure to shitcoins is addictive and very difficult to avoid even though it didn't take me long to conclude and limit myself from almost every shitcoins. 20% target is not supposed to be difficult for any investor who understands bitcoin investment. Bitcoin is the only and most reliable cryptocurrency and deserves more than 90% of your investments fund. The more you invest in shitcoins, the higher risk of getting stucked in it and the less funds you introduce to your bitcoin which would delay your accumulation target.