Sure, you can do that, but keep in mind that it doesn't guarantee your wallet is immune to potential flaws in its code. Whether those flaws are malicious or bugs they could open up the access to your funds for third party. Using multisig reduces this risk. That's because for an attacker to compromise your wallet they would need to exploit all cosigners. Regarding bugs existing in all cosigners, the odds of it is the product of each one's individual risk, meaning the overall risk drops significantly as you add more diverse cosigners.