Tiny things

it's definitely Grady's fault

Nice work Johnny Bro! 1-2 deep magnets 5 or 10 mm with green stuff and green under the bases.

Magnets 5x1mm

Magnets 10x1mm

I would suggest picking a force that can infiltrate as a starter (raven guard/alpha legion) and then add other formations from other legions as you see fit.

At the 1000-1500 pts infantry will dominate.

I am coming to the conclusion that a rounded force needs it attacking (infiltrating elements) and then a solid defence/follow up component.

You could of course just go for a ludicrous amount of Imperial Fists like me a loose a lot

You could be a particularly special kind of sadist and do both. I have been considering a minimum demi company of wolves as an ally for my Solar Aux, 1 Commander, 8 stands of Tactical Marines (thinking an additional 8 missiles launchers to make the handy) and a unit of 4 lascannon dreadnoughts. Also pondering Rhinos to move them up a bit then drive then off and hide them on the flanks to stop outflanking units.