The heroes and villains in the game have pretty decent abilities that fit their character. (except for Phasma, that staff strike is pretty useless)
So I am not that afraid they will make crazy weird choices for the upcoming ones.
However, making Obi-wan a bit more defensive would fit the upcoming heroes. Since Anakin will probably be far more focussed on attack, just as Grievous. Dooku will probably be somewhere in between and I hope Obi-wan as well.
I shouldn't be that worried about attack/defense, I just hope the light side heroes will become more powerful on their own, instead of constantly relying on other characters. Most of the dark side characters are able to do a lot on their own, while for the light side, the power really comes from teamwork. Hopefully Obi-wan and Anakin will be more focussed on being powerful instead of buffing teammates.
Also giving Kenobi another teammate buff ability would make sense (great defender), but Yoda and Finn already have that. That would a bit overkill IMO.