Chappell's no snake, tbh, he's just very socially awkward. I have little doubt his primary motives for going after Sachin is because he thought he could leverage a good relationship to clear the team of dead wood*. Needless to say, he clearly calculated wrongly and probably didn't fully understand team and cultural dynamics at play, etc. An affliction suffered by ever Chappell ever because they can usually just bulldoze their way to the team they want in Australia. They're not sneaky or devious, just authoritarian arseholes who are very used to getting their own way. Probably had to think about that 'together we could rule the world!' line a lot more than he'd like to admit.
*dead wood typically defined by the Chappells as either too old, not an uber gun or, worse, both. Basically if you didn't cruise you way into the Test side on the sheer overpowering odour of pure, oozing talent before your 20th birthday, you should just quit and take up coaching. Have no time for people who might have to *gasp* work for it or *horror* late developers. Was key to letting Harris go to QLD, reputedly (he and Nobes anyway).