Even if the creature is of a kind that normally advances by Hit Dice rather than class levels a PC can gain class levels rather than Hit Dice.
我觉得这句话既然是说“可以”不获得HD而获得class level,那么蕴涵的意思就是也可以获得HD吧。
此外,虽然扮演怪物是SS提出来的,但是srd里也这么说“Effectively, monsters with a level adjustment become multiclass character when they take class levels. A creature’s “monster class” is always a favored class, and the creature never takes XP penalties for having it.“。可见,这也是核心规则的一部分。
SS我没看过,也不知SS中怪物HD和职业等级的换算关系。但是以我所见,怪物HD并不比职业等级强,那么PC愿意这么选择,大可以随他的去。这不会对平衡性带来显著的影响。