I think it was clear that introducing new actual characters in season 3, which is the last season would be pointless - we already are in love with characters from season 1 and season 2.
Which is why Zava, Shandy, Jack, Barbara and DrJake are not really exactly characters,
but they were more like tools to help us understand better the characters we already know and love.
1)…Zava brings the team on a very extreme high, very quickly. Tons of wins with zero effort and all the euphoria. Like a drug. Maybe like a performance-enhancing drug in sports… One montage showing the team going up in rankings shows Ted relapsing back to drinking alone at night.
In episode 5, the drug is still in the system, Zava is still there but… the team is losing. He can’t help anymore. The “high” is gone. Just like with real drugs.
( Alcohol is on this show only depicted as something positive when people drink together, but always showed as something negative when a character drinks alone. For example, Keeley has a glass of wine before sleeping with Jamie in s1, Rebecca when telling Higgins to send the photos to the Sun, Ted always drinks alone only when unhappy; Ted reaches for water when on the phone with Michelle but when she says Henry is with Dr Jake, Ted stops and reaches for alcohol)
2)…Shandy -I think, the writers debated on how to show that Keeley is making mistakes and she’s not the perfect bossgirl Roy saw her as …so they
decided to personalize Keeley’s two mistakes into two terrible humans.
Shandy was hired by Keeley who is feeling alone, dumped by Roy, separated from Rebecca and from Richmond due to chasing her professional dreams. There’s an excuse to hire Shandy - she seems to be perhaps good at the job at first, but mostly, Keeley hired her for wrong reasons.
The pooping lamb turns up every time Keeley is about to make a mistake: first she’s about to hire Shandy, bcs she’s lonely. Shandy showed us Rebecca was wrong - don’t always hire your best friend.
3)…Jack - the second time the lamb is in the same building as Keeley, it’s right before she makes the 2nd huge mistake - hooking up with her boss.
Jack shows us that a “Rupert” can sometimes be hiding behind a young,pretty female face, too.(Rebecca literally compares Rupert’s manipulative love-bombing to Jack’s.)
4)…Barbara showed Keeley that a slower, professional relationship can actually pay off.
Keeley is not the perfect businesswoman Roy thought she was. Roy explained why he dumped Keeley when he talked about Chelsea at the end of episode 2.But the reality is different; Keeley can’t easily become Rebecca overnight. She’s had it way too easy in season 1 and season 2.
Keeley’s biggest strength is also her biggest weakness, as shown in season 3:
relationships, empathy, her need for close friendships.At the end, just like in season 1, she’s, again, happy to choose to be at least single.She’s had her heart broken 3 times by 3 people in 3 seasons.
She hopefully learned, thanks to Barbara, to take things slowly.
5)…Dr Jake is the only person who would cause Ted to relapse. We watch Rebecca relapse a bit, revert to who she was in season 1, but then get back up, after finally being reminded again in episode 4 that Rupert is not worth it,
we watch Jamie relapse in Mom City and a bit during his fight with Roy in the finale,
we watch Roy and Keeley revert to their old mistakes from season 1 a bit.
Ted Lasso would never relapse to obsessing over his exwife and drinking just because Michelle is dating. He finds out she’s dating in episode 1, but
he is okay in episode 2.
Only something as shady and gross as DrJake could have him relapse as well, and, just like everyone else,
get back up there, stronger than before.
I always thought Zava was their way of showing that Ted, Beard and Roy are struggling / regressing without Nate to contribute on strategy.
If you go back to season 1 pre-Nate’s contributions, and Ted and Beard have the team funneling the ball to Jamie on at least one occasion.
Hiring someone new, Zava, and regressing to that strategy shows that they need to find a way to fill the niche that Nate once occupied.