Tyranid/Dark eldar 1850

After always having to make the hard decision of which of my 2 armies to take i've come to the solution, yust trow themm togheter! and seeing how they don't get along standing side by side very well they can sit in reserve.

Combined arms: 875

Hive Tyrant, Wings, 2x TL Devourers, Electoshock grubs 240
Hive Tyrant, Wings, 2x TL Devourers, Electoshock grubs 240
3x Ripper swarms, Deepstrike 45
3x Ripper swarms, Deepstrike 45
Hive Crone, Stinger salvo 165
Mawloc 140

Allied detachment: 245

1x Lhamean 10
5x Kabalite warriors, Raider, disintregator 95
Razorwing Jetfighter, dissintegators, monoscythes, splinter cannon 140

Allied detachment:245

1x Lhamean 10
5x Kabalite warriors, Raider, disintregator 95
Razorwing Jetfighter, dissintegators, monoscythes, splinter cannon 140

Allied detachment:225

1x Lhamean 10
5x Kabalite warriors, Raider, disintregator 95
5x Scourges, 4 haywire Blasters 120

Formation detachment:260

Scalpel Sqaudron: 260
5x Wracks, Ossefactor, Venom, splinter cannon
5x Wracks, Ossefactor, Venom, splinter cannon

Total:1850

It's a novel idea. The first thing I'd suggest is ditching all those allied detachment for a single CAD and losing the extra tax units for more substance. I'm one of those that doesn't believe scalpel makes a viable null deploy but if it works for you cool. You should do well in the skies but I'd like to see more dedicated anti tank.

I wasn't sure if it was legal to yust take a Dark eldar Cad, if it is realspace raiders would give me all the stuff im after for cheaper indeed. Drop the extra tax and take and add another unit of scourges.

The 3 sources of CAD/CAD/formation is more likely to be accepted than 5 detachments simply because of what allowing 5 detachments can potentially enable in other forces. In fact 3 source is usually the standard now days. RSR is an option as well but you need to justify the trade off of cmd bennies.