Well, there actually ARE those two builds in HoML (you choose one of those class features at chargen). I'm not sure why mine are NECESSARILY samey, they have differing class mechanics and depending on what choices you make the likely boon/power choices you would want will be different. I mean, its not like 4e sorcs don't all share the same power list, they do! So, in terms of the diversity of one build vs another build of the same class, HoML has lost nothing.
Now, it is more of an open question when you discuss diversity between classes, since Wizards and Sorcerers can technically take all the same powers, if they want. Wizards have controller build options, sorcerers are strikers, and they start with different implement proficiencies, thus probably favor different stats, and that will likely feed into which secondaries are optimal for each one, and thus overall you will likely find CHARACTERS won't overlap a ton in powers. Honestly I care less about the diversity of hypotheticals like classes, as you play a character, not a whole class.
Let me rephrase.
Burning Spray is a Sorcerer At-Will. It is a solid choice for anyone wanting a decent multi-target at-will option, especially if they intend to focus on dealing fire damage, or want a way to set things on fire from a distance. It is especially useful for Dragon Sorcerers, however, because it has a subclass-specific rider that causes the next person to attack you in melee to take Fire damage equal to your Str mod. This doesn't just play into the (sub)class fantasy of
breathe fire on your enemies, it also enhances the (sub)class fantasy of being able to go toe to toe with your opponents: the rider provides you protection against enemies who try to harm you in melee, feeding into the "beefy caster" concept that the Dragon Sorcerer represents (and has represented since at least the Dragon Disciple PrC; something even 5e recognizes.)
Conversely,
Chaos Bolt is a Sorcerer At-Will that deals solid damage at range, has a good damage type in Psychic, and targets Will making it fairly reliable. However, in the hands of a Chaos Sorcerer, it becomes an engine of
massive multi-target damage...IF they roll lucky. Because every time the attack roll is even, they can effectively make a lesser version of the same attack against a new creature (but never against one already hit this round.) That's very useful, and it plays into the subclass fantasy of toying with unstable, unreliable powers that
might do fabulously awesome things...or might be kind of a dud.
I consider these interactions to be extremely important to the structure of 4e. Without them, and
especially if they're gone AND all powers are available to all classes always, you have removed much of what makes it interesting to construct a character and a good portion of the tactical value in making choices. Just pick whatever power is strongest from all classes. It's the augment problem writ large; spam your best augmentable power until you run out of PP.
In removing subclass-specific riders and making all powers universal, you have removed a core pillar of support for fulfilling those (sub)class fantasies. Unless your baseline features are up to the task of carrying that weight all by themselves, and I am more than a little skeptical about that, you seem to have done what I said: impoverished an important part of 4e by over-genericizing its components.
