Forget about Wasabi. That's a bitcoin-only wallet, so it won't serve for the purpose you want.
I think Cake wallet is easier to use than Stack Wallet. If I remember correctly, Stack wallet requires that you generate a new seed for each cryptocurrency you want to use with it. That may not be too big of an issue, but it kind of defeats the purpose of using a multicoin wallet. You could as well install multiple different software wallets for each coin (if they are available for Linux) and get similar results.
A quality, open-source hardware wallet beats a hot software wallet any day of the week. Your keys are stored in chips on the hardware and not on a device that is constantly connected to the internet, always communicating and has God knows what else installed on it that might be malicious or turn malicious with time.
It's the holiday season. If you are thinking of buying a hardware wallet, now is a good time for it. Many brands have discounts during this period.
3. You've got unstoppable wallet. But i wouldn't say it's necessarily better.
Unstoppable Wallet isn't available for Linux, only Android and iOS.
Unstoppable wallet is another good multi coins wallet but it has synchronizing bug once in a while. However, cake wallet is a good multi coins wallet and has the swap features making it somehow unique from the rest software wallets that are open source and noncustodial multi coins wallet.
Unstoppable Wallet also has swaps. It supports THORChain and the Maya Protocol. But as I said, it's not available on Linux.
HWs costs on average between ~ $100, so unless your cryptocurrency investments are more than $100, there is no point in buying it.
OP might want to increase their portfolio in the future, and that $100 investment could soon become $1,000 or $10,000.
And why exactly these three wallets? There are so many wallets available as browser extensions that support multiple currencies and work perfectly on Linux. I personally use Enkrypt - it fits all my needs and I have no complaints.
There are also web wallets, which are even more convenient.
Convenience and security are two very different things. Web and browser wallets may be convenient and easy to access and use. So are custodial exchanges. But in terms of security, browser wallets are the worst type you could use.