Well, it turns out that newest run of mine did actually beat it(I think the final wave type is around 60min mark). There were a few bugs, loads of saves(some saves were 3-5 seconds apart...), and plenty of mini-strats that came with it. Since there were already a few people who finished it with leo's, I wanted to take up a similar challenge you did and beat it with static defenses only(or at least no juggs or dreads ever built). In terms of units, I used:
2x Nemesis(although this was only built for me so I could see its exact weapon range, destroyed immediately after produced)
...And a lot of engineers.
Replay, saves, and end-game image posted below. One of the bugs I had actually helped me a lot(definitely with experimenting), but I think you can still do the static def. strat w/o it so long as you know the final layout. There's also a few things that I might've done differently if I went through it again. I'd explain more, but I prbly shouldn't.
Saves and Replay: https://www.dropbox.com/sh/bpuad099hqoxvp6/AADrwUzOpGZb7H3vEpxwhUZoa?dl=0
End Game Image: https://imgur.com/a/9ZyMt