Let's take a quick look at some of the reasons why. Most teams will meet with limited success laning OTB so both wires are makeable. A few useable lanes exist but expose the shooter to counter-lanes. The quicker teams shouldn't have too much difficulty making a wire the majority of the time.
Even when teams make a wire OTB the dominate feature of this layout is the gatekeeper aspect of the four insert Temples. Each one serves as the primary access point to a wire and the primary means of denying access to the wire. (The pink arrows indicate the direct confrontation created at these gaps feeding the wires.) Much of the early action and focus will revolve around these Temples and much of that action will be direct gunfighting. The only other primary option to control the wires comes from the (orange) CKs. Their placement (and size) limit both their effectiveness and defensibility--they will be hard to live in once opponents are on the wire(s). The result is contain or control from the interior of the field is at a heavy disadvantage further pressing the Temples into direct confrontations or else give up access to the wires.
Once on the wires most of the available shots are on the same wire (or that half of the layout) until the fifty--or beyond--is reached making the standard of play battle to reach a wire, battle that wire to get upfield, eliminate your wire to get positional opportunities to finish off your remaining opponents.
Breaking up the wire-centric focus are the upfield options in the center of the layout. While the M is playable I've focused on the props marked in green to represent center play objectives. The goal is to disrupt your opponent's breakout and rapidly attack one or more of their primary positions or early transitions in order to gain a quick body count advantage. Thereafter the center of the field can be used to deny counter-movements and pin the remaining opponents in place. The MT is better suited to the task as it is more defensible and has better lines-of-sight than the Can.
Players on the wires have limited ability to contain or control other wire props. For example Snake 1 cannot stop his mirror from bumping to Snake 2 so for players on the wires the game becomes a race to the 50 and against opponents on their same wire. (The d-corners can contest wire movement, unlike the snake corners.)
Finally the snake wire is more easily dominated because it is more difficult to contain and/or control movement on that wire. Center (green) positions have some options as do the (orange) cakes but all are limited. And the corner TCKs are not in position to deny movement up the wire but are able to aggressively attack the insert (gatekeeper) Temple making gap contain very difficult. While the snake appears more open and exposed it should be easier to push bodies up that wire.
This is the kind of layout that could easily engender upsets.
From 1 - 10 on some varying factors.
Plays Fast. (promotes quick points) Fun to Play. (players enjoy it) Easy to Ref. (clear and open lines-of-sight) Balanced. (allows teams to play their way) Spectator Friendly. (solid action and exciting play for the knowledgeable fan)
Plays Fast: 7 (Win the gunfights, win the war. Still kind of a crapshoot.)Fun to Play: 6 (If you've always wanted to be a front here's your chance)
Easy to Ref: 5 (Center of the field action could be tough to control)
Balanced: 3 (Defense? We don't need no stinkin' defense)
Spectator Friendly: 6 (Boring timid teams make for boring timid paintball)