Thanks for the suggestions Hazzer22.
I played a game the other night against blood angels and practically tabled him (winning 12-7).
I know blood angels are struggling despite the new codex especially with the big FAQ April 2018, and would expect to win that match up, but I'm just looking at how units in regards to mortals wounds perform. Stand outs from this game -
Scourage with haywire blasters - took 3 units of 5 and they murdered stuff, deepstriking into cover in my deployment zone turn 1 and murdering 2 tanks. then proceeded to shoot down a storm raven on turn 2. A+
voidraven bombers - one got shot up turn one but survived and still managed bomb some primaris hellblasters on my turn one with the other voidraven killing 4 out of 5, rolled well. the Dark scythes then went to town on some other primaris marines for the rest of the game. B
Mandrakes did well, deep struck in assassinated a primaris lieutenant assaulted and eventually killed a primaris captain was well. B
Reaver Jetbikes - was trying to get the fly by strat. to work with them but I think it works better with red grief, obv. The did hold up all other unit though. C
Wracks with Ossefactors - did ok but obv. not enough of them to truly see what they are like. C-
Another thing I need to fit into the list, is phantasm launcher, for the strat to possibly do motral wounds along with grots (which I know are really strong unit anyway, but mortal wound wise.)
strange list to play, I'll have to try it a few more times to see what works best etc.