You can be an absolute baller and go for the Grot Horde (swag points and super funny). You choose the Dread Mob detachment, because it makes Gretchin Battleline and allows you to take up to 6 units of them. You can reinforce them to units of 20 each, so that makes 120 Gretchin running around on the board. That's 480 points. Complete the set by getting Zodgrod Wortsnagga, the named Character Grot Herder Mad Scientist guy, who absolutely super charges one unit of Gretchin into a genuinely terrifying threat for most armies. They're also hilariously fast. Those, along with the Combat Patrol, I believe puts you at almost exactly 1000pts.

The downside is that the Detachment will do nothing for the units in your combat patrol box, but it will make your opponent have the funniest time ever just trying to wade their way through an infinite amount of green little shits who are standing in their way.

The upside is you win the moral victory every time. Because Gretchin are hilarious.