The base set didn't have enough for the circus to really hit their stride. Most builds were more about getting a hex to use for things other than the actual hex. Now, the deck was solid but it had the problem of an inconsistent stud in Mongwau and a low starting influence; this led to many slow starts, and with The Sloane Gang being a really effective early game shooter, Wendy starting most games and Morgan Cattle Company getting a bit of a cushion in the time they needed to set up their income engine and you had a rough time in the base set with The Fourth Ring.
Now the first saddle bag New Town, New Rules went a long way to fixing those issues. Solid hexes at good values for a deck that needs to make the clutch pulls: Forget and Paralysis Mark. A source of cheap influence in Dulf Zug and a useful body down the road in Slade Lighbody. The hexes gave the circus a win condition and a way to control movement and deal with some of the more troublesome characters in the game.
While Double Dealin' doesn't add much for most people it seems, I like Leon Cavallo as an alternate starter that will help hinder the opponent's movement and he gives me another outlet for the hexes. This allows me to spread the hexes out to avoid Unprepared shutting down my turn. Fetch has been another card that has really helped get the right card into my hand if an opponent cheats. Baird's Build and Loan fit the values and helps with my light income.
I can see several changes to test, but right now it has been pretty solid. I run the Unprepared for mirror matches, but I could see dropping the Unprepareds and adding in another Recruitment Drive. You could split them and see which works better for you, the same could go for Rumors/Reserves. With the two slots still left I would run two more Hex Slingin'.
The Fourth Ring
Starting with 2 wealth, 1 income and 6 influence
♠ Spades (* starting posse) (13)
1x A Dulf Zug*
1x 3 Mongwau the Mighty*
1x 6 Wilber Crowley*
1x 7 Arnold McCadish*
1x 7 Leonardo "Leon" Cavallo
4x 8 Steven Wiles
1x 10 Avie Cline
1x J Kevin Wainwright
1x J Tyxarglenak
1x Q Jia Mein
♣ Clubs (12)
1x 8 Reserves
3x 8 Rumors
1x 10 Recruitment Drive
3x 10 Unprepared
2x J Hex Slingin'
2x Q Takin' Ya With Me
♦ Diamonds (10)
1x 8 Circle M Ranch
1x 8 Pat's Perch
1x 10 Carter's Bounties
1x 10 The Union Casino
1x 10 Baird's Build and Loan
1x J Jackson's Strike
1x J Undertaker
1x Q General Store
1x Q The Pharmacy
1x K Railroad Station
♥ Hearts (17)
2x 7 Fetch
4x 8 Paralysis Mark
4x 10 Shadow Walk
3x J Forget
4x Q Blood Curse
Jokers (2)
1x Joker (red)
1x Joker (black)
"Have you paid your dues, Jack?"
