This, and also competent VC's (and Heroku's VCs are top-notch) don't want much more than a third of the company in a single round, as it makes it far too diffic

This, and also competent VC's (and Heroku's VCs are top-notch) don't want much more than a third of the company in a single round, as it makes it far too difficult for the company to raise capital that it may need in later rounds.