First off all, this is not my creation, i wanted to contact original author but i can't find him on this page.
So all credit  goes to respective author+ his name will be down at description + in mod.txt
I'm not good modder so not all things are fixed.Also this mod is more intended for higher diffs than the lower ones, however it will work on all difficulties.

Second of all you must drop this folder into mods ,otherwise game will crash-  Must install-Cloaker bomb fix  .I'm no great modder so its as a seperate mod instead merged in one.

I higly reccomend Full Speed Swarm mod, made by TDQL

Assault overhaul
Original mod got broken after some time and wasn't updated, it was crashing and captain Winters wasn't spawning at all ,also enemy cap that can be present on map was very low. 
Tweaks  and fixes made:
Mod no longer crashes.
Captain Winters will spawn on all difficulties where he should.
Captain Winters minion count is 18 now, his damage resistance buff starts at 30%.
Captain Winters spawn check interval lowered to 60 seconds, so he should  always appear.
Enemy count that can be present on map have been made higher, it's around 45- 50 enemies , on some occasions it can be 60, they also spawn faster.
Assault will now end after 4:30 minutes ,it is unlikely that it will end prematurely as spawn pool is high.
If you have atleast one hostage then assault will be delayed longer (1:30 minute), to compansate the high enemy spawn and count, this is only valid when you have hostages and you need to have hostage at the beggining of control phase( music is calm).
Fixed crashing when cloaker was dropping smoke bomb.

Optional- gensec elite with smg will spawn. - adds more diversity
Optional- gensec elite with auto shotgun will spawn. - adds more diversity + those will spawn at one down and they are dangerous.
Side effect of those two files- gensec with jp36 will spawn sometimes on one down .

Issues:
Incorrect enemies spawn, for example special  and fbi units  and will spawn from normal . Green fbi will replace most blue swat units from normal to very hard.
Optional- if you have one of optional files , you will crash on boiling point, so remove it to being able to play that map, other maps work fine.
Optional - if you have one of the optional files , the enemies will spawn at lower difficulties than they should.

Credits goes Brand0 for creating this wonderfull mod, i just made a fix for it.