The employment contract guarantees the equity subject to board approval. I'm not quite sure why people are making such a big deal out of this.
> The board agrees all new employees get X options with a 1 year cliff and 4 year vesting without additional approval so long as total options granted does not exceed Y.
The board only needs needs to be involved if X or Y need to be changed.
Having the board bother themselves with every little hire is just ridiculous. They have better things to do. Plus if the options are defined on paper the company can't be accused of favoring certain classes of employees differently.
An employee who fails to receive full compensation can receive free legal help from a range of organizations with very deep pockets. In many situations companies have a significant advantage, but in this case they really don't.
Sure, people and companies may be completely irrational, but competent legal advice will tell them to leave this one alone.