If it’s night time and fairly dark out why not just make a haze so it helps obscure us as we stealth by?

(Think about how I am using the illusory space. If I can use silent image to create a 15 x 15 foot cloud of fog that covers the party entirely, I am doing the same with an illusory crowd of people. The space in between the people is also apart of the illusion. The spell is limited by the fact that the image is silent, but if I already have a crowd of people walking the illusion is complete with sound. This is my case for the use of this spell.) 

Quote from Teechu >>

If it’s night time and fairly dark out why not just make a haze so it helps obscure us as we stealth by?

(Creating a cloud is different from creating a crowd of people though.  The cloud of fog will obscure sight at the party, and could even be used to help with sneaking perhaps, although it might make an observer curious enough to investigate why there's a single small cloud of fog moving through the city at a walking pace.  I might even be okay with just making an illusion of a crowd of people instead of a single person - though I'm still not certain if the spell is intended to work that way.  The problem is making an illusion of a crowd of people that are meant to overlay and disguise real people where the illusion has to be perfectly in sync.  Not sure if you saw my edit of my last post since you posted at about the same time, but I'd accept making an illusion of a single person as a disguise and attaching it to them so it'd move with them, I'm not so sure about being able to do that for 8 different people at once with a single spell)

(The people I am creating are wide and tall with little Kobolds in between any open spaces. People are also carrying tall spears to cover the Taller characters. Any negative space will be filled with the illusory movement of a crowd. I am trying to get us through this town and I am using one of my two spell slots to do it. Is it possible or not.) 

Edit: (I am saying that the illusion doesnt have to be in sync because all moment and open space in this image is an illusion.)

Double Edit: (My Character has no attack magic, this type of shit is all he has. Please understand that I am not trying to break any rules but use these spells to their limit) 

(Your original post just talked about making you look like a badass group of town raider, which I read as just disguising you guys, not making an entire crowd with you included as part of it, was a full crowd your intention?  Silent image - at least by my interpretation - wouldn't let you just make the taller characters effectively invisible using the negative space.  It could have the illusion of something covering a space, but can't just make it look like nothing's there, so observers would be able to see between tall spears to notice the 6-7" tall characters walking in the group.  I might let you at least attempt the full crowd version as opposed to perfectly disguising the party members, but probably with penalties. So far you haven't seen any groups larger than 6-8 looters at a time moving through the town, and haven't seen any long spears, so you'd still look out of place, just less so than you do now.  Enough so that if spotted, the observer would at a minimum either make an investigation check, and possibly see through as a result, or confront the crowd, requiring some form of persuasion/deception/etc to get past.)

(A crowd to hide in was my intention if I cant cover up my party members. I am trying to create a group of 9 people holding bags and loot. The bags, Loot, and equipment provide enough cover of the negative spaces to make it easy for my party to hide. The spell has an INT DC of 13. If you got problems with that then I will just make a Huge Dragon that is walking down the streets and we will hide within that image). 

(I'm not sure a group of 9 people provides enough coverage to hide another 8 easily, but I'm willing to let you attempt that version.  Would be easier with just the 4 party members instead of having extra NPCs with you increasing the group size.  It'll basically just be replacing the stealth checks to try to sneak through with other checks to not be spotted as fake/bluff your way through)

(Yes) 

(So do I need to roll something else?)

(If you guys are all happy to go with the illusion route, nothing yet.  I'll update whats happening.  Any arguments with taking that route?)

Quote from VanderLegion >>

(If you guys are all happy to go with the illusion route, nothing yet.  I'll update whats happening.  Any arguments with taking that route?)

We can give it a chance

I am fine with the illusion route, although I am a Kobold I don' want to be noticed by the other Kobolds because they can notice that I am not one of them.

Pops casts an illusion over the group to attempt to disguise them as just another group of looters.  You pass several seemingly empty houses as you walk up the street, then, as you start to walk past the final house on the corner, a kobold walks out with a sack of loot.  He looks the group over.  "Where are you headed?" it asks in common.  You can hear more sounds of movement inside the house.

Quote from VanderLegion >>

Pops casts an illusion over the group to attempt to disguise them as just another group of looters.  You pass several seemingly empty houses as you walk up the street, then, as you start to walk past the final house on the corner, a kobold walks out with a sack of loot.  He looks the group over.  "Where are you headed?" it asks in common.  You can hear more sounds of movement inside the house.

 

Deception: 7

Persuasion: 4

(You have advantage on those rolls ) 

Pops will Help by speaking in draconic as one of the Kobolds in the crowd saying, "Damn, Goodie Cutters coming fo me gains!" 

Advantage means you roll twice and take the higher

the dice roller also has an option for advantage which does it all for you