With respect, I don't think that is correct. The takeover regime applies only to public companies, like Arsenal Holdings plc, or companies which have been publicly trading their shares.
Liverpool Football Club and Athletic Grounds Limited is a private limited company so the 'takeover' requirements do not apply.
In any event, the 30% does not operate in the way you have described. Acquiring 30% of a public company obliges you to make a general offer to the remaining shareholders to buy their shares. It does not oblige the remaining shareholders to sell their shares to you, although minor shareholders may certainly like to cash in.
FSG could agree to sell any number of shares to the consortium. If it retains more than 50%, then it effectively retains control of the club. If it sells more than 50%, then it cedes control, which means that the price would be significantly higher (as good as selling the club) The dispute over the exact percentage would be important mostly because it affects the valuation of the remaining shares, assuming that FSG intends to sell the remaining shares as well, at some point. In addition, a party with more than 75% would be able to pass a special resolution unilaterally.