yes, in Empire 2 i seem to remember classes like Valkyrie require a Title unlock or at least, in the beta-versions i played through i was never able to create a Valk from scratch.
Berserker/Almighty classes are 100% locked with ridiculously steep requirements (titles).
as
Courtier says in Empire 1-3 games the Summoner classes is GREAT as they learn summoning
and Alchemy
and Psionics. Their Attributes are horrible, of course, and but i mean, what else do ya want.
i actually do not really recommend spending tender-loving-care in having a Ranger in your crew even though in my playthrough i had one. it is precisely because i had one from beginning to end that i can wholeheartedly testify that unlike Starfish's later games (Elminage series on PSP/PC) where they have
awesome Bows for the ranger-type class (plus a class-specific attack ability that is insanely good), in their Wiz Empire games the ranger is literally just a gimped Fighter with super slow access to Alchemy (he learns them almost at the same slow rate Bishops learn their own respective spells, i.e. SLOW) but i can't recall any good bows whatsoever.
the Wiz Empire-only class of the female ninja, the Kunoichi, is super OP however and recommend building one (towards one, as making one from initial char gen would require like 3 days re-rolling bonus points) so make sure make your initial party Thief female and evil. (although there is shit later, fountains/items/etc, that can change her alignment and gender, and actually i do believe there is also a Mask-helment for evil-females that transforms into a Kunoichi).
There are also like 3 different items that transform Spellcaster-types into Summoners as well (2 whips, and some other shit).
The male Ninja and the female Kunoichi use different gear, and the Kunoichi is the only one to get access to insanely OP shurikens that behead like crazy. Other than that playing the Wiz Empire games as you would play Wiz 1-5 is just fine as they are literally Wiz 5 "on steroids", etc. Starfish lurves Wiz 5 (the entirety of Japan does) and they have honed and polished the Wiz 5 blueprint to a blinding golden sheen that is unsurpassed by even the original Wizardry titles.