Ahh I misunderstood then
The fun in having 2 very similar character is figuring out strategies where they support each other and can be interchangeable. So you come up with ways tactics where 1 supports the other or prepares the way for the other.
With 2 mages you have 5 different schools of spells to choose from. So they aren't really just 2 identical mages. You pretty much have to cover the different types of magic or you end up in fights you just can't win.
For example a lot of demon types and fire elemental types. If both mages focus on pyromancy then you're pretty much screwed for that fight because all your spells end up healing the creatures instead of hurting them. Even the creature you can summon will heal them instead.
So that's why you have to split the schools up in some way.
Water and Air are somewhat complementary
As are earth and fire
So you pretty much have
Scarlet: Fire+Earth Rod: Water+Air
or
Fire+Water and Earth+Air, then in a single round you can pull off certain combinations like rain to make a poll of water and lightning to stun everyone in the water
ect
But for Bow/Rogue/Tank each has just the 1 school so there wouldn't be any variation there.
I'd suggest searching for people talking about "power builds" or their "ultimate builds" and see which ones sound fun then try it out. Or just try stuff out, but that can get frustrating each time you make a choice that turns out to be a dead end or just uninteresting.
With rogues and tanks I think it would be boring
At least with the archer you can use complementary arrow types
Poison Gas + Fire/Exlplosive
Steam Cloud + Shocking
ect
With tanks and rogues... pick up lots of barrels drop them early in the fight and break them?
There isn't any taunt so you couldn't do an MMO style rogue ping pong
Where you have a rogue on each side of a target and then argo from back stabs causes it keep turning 180 degrees
Ultimately there are fights you have to go through that some classes just aren't suited for. There are some creatures that are healed by all elemental damage, which negates 4 of 5 schools of spells. Of course witch craft has "death punch" which has a long cool down but does a HUGE amount of physical damage.
In the later game there are a few places where 2 lone wolf characters gets annoying though because of other limitations
Near the end you fight a number of death knigit patrols of 3 or more knights. The cool down on the "remove invulnerability is 3 turns but I can easily take down 2 of them in the first 2 turns.
So the fight got really old
Round 1
#1 buff up; debuff knight; do lots of damage or maybe position for AoE
#2 buff up; debuff a second knight; damage & positioning
Knights move and maybe get an attack or 2 in
Round 2
#1 do more damage maybe kill a knight, if not set both up for #2 to kill them
#2 finish off the 2nd or 2 knights;
still have a 3rd knight that cannot be slowed or stopped in anyway EXCEPT for feather fall. so feather fall the knight away
Round 3
.... ugh
feather fall then do what? a lot of pointless buffs or preparation to kill 1 target in round 4
Round 4
finish the fight.
Oh look more trios of knights, to repeat this exact same process over again
basically the cooldown on the spell make knights annoying when there are more knights than party members
