If I have two commanders both with Strict Orders, can I remove two suppression instead of rolling dice?

No. Strict Orders is a trigger that says when it activates, it may use the strict orders instead of rolling. You can't rally twice in a turn, so when you use the one strict orders, it moves on to the next part of the turn, making it impossible for the second one to trigger. Hope that helped!

Thanks for explaining it to me!

No but you would have a back up should your commander die.