This is going to be a long one...
Okay, can we talk about the rounds of chess matches that happened in Vincent Blake's ranch at the end of TFG?
And these were the conditions:
Toby - he'd get to go back in hiding and no one would be ever the wiser on who he was and what he was doing.
Avery - she'd get to get Grayson back from "captivity", her loved ones wouldn't be threatened again and Sheffield Grayson's case would be kept a secret (therefore not threatening her and Oren's positions)
Eve - she'd win all five seals aka the keys to Blake's kingdom
Toby - he would have to announce his existence as Toby Hawthorne
Avery - Blake would let Grayson go and never hurt her loved ones again, but the Sheffield Grayson case would be exposed
Eve - she would only win one seal
Toby - become Tobias Blake of his own will and stay in the ranch forever
Avery - she'd have to do Blake a favour (blank check $$$)
Eve - Blake would let her be in the service of whoever he gave her to (that sounds pretty unnerving esp the analogy he lives by that is "boys will always be boys" like I don't even wanna imagine what he would do to her)
If we observe all the terms closely, the person with the least to lose if they lost both matches was actually Toby. If Eve lost both, like I said, something ugly would happen. If Avery lost, she could damn easily lose her inheritance if Blake just said he wanted everything. So Toby decided to throw Eve's match because he didn't want her to lose both and warned Avery during their match to not be overconfident. Which meant that he was pretty set on protecting both his daughters which led to him becoming Tobias Blake.
I personally believe that Toby didn't want to win the match against Avery because he didn't want to come back as a Hawthorne (as I believe that he was ashamed of his father's actions and he wanted nothing to do with the name).
On the other hand, the person with the most to gain if they won both, would be Avery since Eve would probably (she should) have been okay with just one seal. But as we know, Ave had plans of her own so she threw her match and let Eve win.
What I'm saying is... I think Blake set Toby up because he knew that Toby would choose to protect his daughters. Taking that into account, the person who'd win both would either be Avery or Eve and at this point, Avery would have more to lose than Eve. I feel like he expected Avery to beat Eve since the results of that would allow him to still have control of the board.
Avery would win both but as she mentioned through the thoughts in her head, Blake could still get her via other methods. Eve would only win one which meant Blake still had four other seals and as Blake is most likely biased towards males (so he probably thinks females are incompetent), he would just give them to other people.
But at the end of the day, Avery was just too smart for him to handle so he didn't have a choice but to have a truce with her.
Moral of the story, don't mess with the Heiress.