@Corbett, yep, tutorials take manpower. That’s why almost every other uni in England besides Oxbridge (and a handful of others) don’t offer many weekly tutorials of 1-2 students any more.
BTW, Sarah Lawrence, NCF, William Jewell’s Oxbridge Honors program, and Ohio U’s Honors Tutorial College also offer tutorials.
So schools not fighting for the top of the rankings may be more incented to offer special tutorial-style classes (as a draw to bright kids).