Such is life. But the story of your gang now about revenging their fallen leader and which likely lad/lass will rise up and take over the gang. Its not just about winning... its the stories you tell as you play. So now you will play up hill a few games. Or a lot of games. Maybe even every game.
But you can also petition your house for some help... they might give you some sympathy. Besides there are multiple ways to win. Sure the Eschers will be richer and have the turf ... probably for the next round too. But concentrate on surviving, depending on the scenario, you might need to bottle early ... but the lower your rep the more chance your house will send help. Or, ignore turf and creds.. play each game till you kill an Escher then bottle. Your campaign now is to kill/maim/sell into slavery every Escher who brought down your leader. And to be honest its much better to have your leader killed now, while he is only 245 creds and before you got to see him crushing people every game.... trust me, its much harder seeing a much used and favourite, 10 game, levelled up twice legendary bad ass get minced by some cheesemonger Corpse Grinder Renegade or turned into goo by a Van Saar that still hits you on a 2 despite you being in cover. Maybe your story is not about to gangs contesting for dominance, but you are Palestine to the Escher's Isreal, the 24th at Isandwala or the Warriors trying to make it back to Coney Island. A small but determined gangs resistance to an overwhelming force. Assume that the Eschers are taking over and your job is to make this as costly and troublesome as you can. On a tight budget. Maye you get massacred along the way and the campaign ends when you gang is all dead and you hope you took down more of them than they did you... Then you can start a new campaign.
My Orlocks in their first campaign lost their first 8 full games, only winning one because my opponents roomate accidently poisoned herself and he had go home to take her to the hospital. Didn't lose my leader, but he and most of the gang had at least one permanent injury, gammy legs and wrecked spines abound. Their campaign was not about winning now but about surviving and trying to hold on to the one turf they were lucky to claim. They took a few goliaths down with them when ever they clashed.
Me second band, still didnt have much luck, they lost a gunfight when the turned up with a melee champ and juves with pistols and shotguns and the delaques had a a missile launcher champion, a plasma gun and a flamer... that was over pretty quick. In another game a bolt gunned my own star juve.. we once again were on the back foot from the begining and didn't make any money for several games.... still they became quite hard and eventually were able to salvage themselves. They were pretty much finished as a potential winners though. We teamed up with the Van Saar in the last game against the Gene Stealer Cult that won the campaign and gave them a good beasting. My Orlocks came out mostly unscathed and the Van Saar took most of the GSC mean tricks.
My third gang is really strong, we destroyed a Van Saar gang in their first game and got lucky with rackets so I had more turf, and crippled the Van Saar gang (killed his Augmek).. Ive not won every game, but my lead is fairly cemented to the top 3 now. Does that mean I am invincible.. no, I still lose. But does it mean the campaign is over? Nope. The Van Saar have no chance of becoming a huge gang... but they are still capable of getting kills and becoming known as being violent and brutal... which is just as good as being the leader of the league or having the same amount of power/gear as everyone else.