I have verified that the bonus objectives are all achievable on Brutal on the current patch. I didn't actually beat the level afterward but I'm pretty sure that is doable.
To kill the enemy commander:
[Spoiler]Equip your commander with a Disintegrator, press D on enemy commander. If you can kill the Mace at the same time that makes the second objective much easier.
To preserve your Ogres:
[Spoiler]Besides the Disintegrator, have a decent primary weapon and some armor/regen/speed modules on your Commander. Your Ogres should start by running east; try to avoid the Mace that was escorting the Commander, but they should be able to clean up the Halberd and Scalpel. In the meantime your Commander should kill the Mace on the east then engage the other enemies coming from the west for a bit to slow them down. Jumpjets or Cloak are useful to escape once you have bought enough time for your Ogres to turn north and make it to your base. There is a Lance knocking around somewhere which you had better avoid but it's probably not a factor before the two minutes are up.
For reference I used a level 6 commander but did not fill all its module slots and had health and time to spare.
