Google does save a copy of your voice commands when you use the Google Assistant app. Learn how you can find and erase your Google assistant voice commands.
Maluuba is a better alternative to Siri for Android as it let you speak in your normal voice and ask it real commands. No real list of commands or template to memorize. If you want to know what the weather is like, ask “How’s the weather?” and Maluuba will search and find out.