Yes, I would love to play against this list with my Dark Eldar.
3+ to hit, 4+ to glance the battlewagons....with 15 dark lances and 20 blasters (also lances) in an 1850 list, eventually something is going to get through.
The reverse is that you've got SIX battlewagons, not one. They'll do the trick nicely.
Also, if you look at the 'Ard Boyz missions from previous years....you only have three troop choices to deal with 5 objectives. Can you squeeze 40 points in somewhere to get yourself a squad of 10 gretchin and a runt-herder to serve as a reserve scoring unit?
And while meganobs are nasty, wound-diversified nobs are nastier. There are things I would do differently, but having not played this list, I can't really comment on it - it looks potent. I'm curious what taking out a single battlewagon and a unit of meganobs to spend those points elsewhere would do. That would give you points for a Loota squad and a gretchin squad. I'd think a warboss would be nice (to make a nob unit a troop choice) and you *can* get 5 battlewagons side by side with the
KFF covering them all with the buggies out front (also getting cover). Not having the ability to split your forces apart isn't really a detriment either; you want to stick together in a moving wrecking ball.
Eh...just my rambling. I think you have an incredibly potent list here. Any game is rock-paper-scissor, and while
DE might do bad things to you with raider spam...you're not going to see many
DE players at 'Ard Boyz. I play
DE and love them...I'll be taking them to probably every tournament I go to this year, but they won't be going to 'Ard Boyz; they just don't scale up in killing power to 2500 points well.
Like I said; my playstyle is shifting and is a bit different than yours; but I think diversified nobs are clearly superior to meganobs - the rest (Lootas, warboss, etc) is personal playstyle.