But can they really do this given how things were set in motions in TASM2 ? That is the big question. Because honestly, I don't think the best writer could all of suden make, lets say The Rhino, a compelling vilain. Even Harry's Goblin would be a real pain to flesh out in the next film. And if the plan is to keep on going with the Sinister Six nonsense with even more vilains and new characters put in the mix then I think the film is doomed from the start unless it's penned by the new William Shakespeare (or his ghost writer

). Plain and simple.
They need to find a way to distant TASM3 from the mess they started with TASM2. Maybe they can play the flashforward card and have Peter about to graduate from college to change the perspective on the story and on the characters and introduce one non-Oscorp related vilain that reflects the themes of the story (and not random vilains that just look "cool").
Make the film about Peter, not about his relationships (like the first 2 films in the series) or his opponents (which is the route they seem to be taking), but the man himself. Go the Skyfall route god dammit ! Is it really that complicated ?
And on a strict business perspective the S6 just don't make sense anymore. How would you justify putting even more money to produce the next film while the franchise is plummeting ? If they spent 255M for 3 vilains in TASM2 odds are they are not going to spend less on a 6 vilains sequel. Even if they cut back on marketing that won't be enough to make the next film even remotely profitable in theaters with another probable drop in BO earnings.