Wat version? 5.84c or 6.37b?  Btw ppl tat join tournament usually veli familiar with hero combo ....a last-minute decision won't b able 2 help u much

kenot pick like this like TS said...Lich&co from bad guys how to mix with Rasta&friends.

Btw if ur team got pro chen/rhasta/omni must pick them.then stunner.
For scourge pusher i think broodmother,leshrac,death prophet.

But If just wanna look cool pick all knight team la...

holyknight,omniknight,dragon knight,rogue knight...

there are things that u should know

how good is a hero in lane control, how well does he do in war (combo or together ) , what can he do in late game

all these have to be looked at..  ( BTW avoid putting a melee hero to solo  )

hero that are good in lane control are

Viper , Warlock , LoA ,

since its a Scourge VS Sentinel

and its 4v4 means that two hero will solo meaning Scourge have better chance winning in lane
but beware of viper i dont think any hero in sentinel can 1 on 1 with viper even syllabear will get raped by viper 1 on 1

i think if the player have around the same personal skills scourge would have higher chance of winning ...

enigma is too easy to counter if he doesnt get BKB fast enough since an EUL can easily  makes enigma useless ...

anyway i think a good scourge combo would be Warlock,Viper,QoP, and SK ( since its 4v4 so SK shouldt have problem getting blink dagger fast )

anyway i think if u get sentinel try avoid getting combo hero :/ most of the time opponent would take AOE heroes on scourge so just use some gay hero than can split push when the Scourge are together

if the sentinel take alot of int hero like enigma,rhasta,cm,zeus just get pugna lol btw the problem with sentinel is their AOE heroes have long cool downs , channelling ,and hard to aim