If the two command are not using the same parts of the subsystem you can just remove the requires part of the command. The only issue can you have with this is you will have to make sure the command is going to stop on its own if you need it to stop. We leave some commands without the requires if the all the command is going is actuating a solenoid and is only going to run once, but for the most part your commands should all require the subsystem that they are using.
Here is a beginners guide on Command Based Java that our team presented at the VA FRC Workshop this past fall if you'd like to take a look.