Wagers are total bullsh*t
They're all practically RNG based if you're not part of a squad.
Note: most of these issues derive from doing wagers solo, not being part of a more organized squad, and instead queueing with randoms.
Wingman wager?
This wager requires you to get the most assists in the game, or a certain amount of assists. Better hope you barely dink enemy players and survive long enough to get the assist, assuming your teammates are actually worth more than a Russian ruble. You get 6 chances to suffer making it to stage 10. Could be worse, but still sucks.
Best squad wager?
You might as well just find a partner to buddy up with, because there's no way in hell you're getting past stage 2 or 3 with this one alongside randoms. Best hope you don't get uptiered, too.
Battle victory wager?
3 chances to fail. You need to win 10 matches out of 13 in order to make it to the end stage. ~75% victory rate. Pray your teammates aren't brain dead. Probably the worst wager there is.
Wing breaker wager?
Enjoy sitting in an SPAA for an entire tank AB/RB match, assuming you beat other SPAA to the punch. I would imagine this one is remarkably difficult, as it requires 5 air kills in a ground battle, but I haven't tried it myself.
Mission Maker wager?
You need to get the first AND last kill for the entire match. First kill is easy, last kill is pure RNG. Don't expect to make it to the end stage.
Thunderer wager?
This one requires the player to have the most ground AI kills, or I think around 18 for the other achievement. Have fun competing with 2-4 other players every match, who probably have a better suited plane than you do.
Golden battle wager?
I hope you're an excellent pilot and have a squad of excellent pilots alongside you, because this is easily one of the most gut-wrenching stakes there is in the game. Don't even try this solo, you're going to hate yourself for it.
The two that I found to be the most reliable wagers tend to be either the "Hero of the Sky" wager or the "Destroy 10 units (players)" wager. You don't need to rely on teammates, you don't need to win, you simply need to score a whole load of kills in AB. The latter is more secure IMO, as it gives you an additional 10 chances to succeed.
There's one more that's significantly easier than the rest of the wagers, called "Destroy 5 units" wager. As the name suggests, you simply destroy 5 enemy players. Very easy, but has little reward, a measly 100,000 SL after 3 rounds.
There's probably several more wagers, but these were just the ones in my inventory.
I like War Thunder a lot, but the wagers are outright stressful for me (and I take it a lot of others). They detract from the game, and they encourage players to not follow what's necessary in their current battlefield, instead following their wager for the whole game and possibly ruining the match.
This stuff needs a re-work.
Rant over.