Re: I may be overthinking this, but
I pretty much agree with with CraterMaker, but to me Overthinking is a negative, if there can be truly said to be an optimal level of thinking, then overthinking it is the mental equivalent of sending it to comitee adding definitions that obscure rather than illuminate. In short over thinking is detrimental and should be a Psyk Lim of some sort or a limitataion bought on either Int or a skill the character is prone to over thinking.
Eg a brilliant mathematician who has an awe inspiring natural grasp of numbers, but frequently overthinks give problem and presents work of dubous academic work on the whole, even if the odd phrase was brilliant.
Id buy that i any nuber of ways, +10 Mathematics Activates on an 11-, half the time he's focused and his brilliance shines through, half the time he over thinks and his work consequently suffers. Or as a psyk Lim, Tends to overthink maths, on failed ego roll 1 is added to the time chart for completion, when new ego roll need be made at -2. Each failed ego roll reduces maths skill by minus 2 although bonues would accrue from extra time. Over timer the ego roll gets harder and eventually there come a point he should give up go think on something else and come back to the problem later, probably itial time for completion to remove a -2 to the ego roll with a further -2 removed for every +1 up the time chart, of course he'd lose the bonuses through extra time, although the work he has made could be the basis for a complementory skill later, etc. If he concentrates and makes the Ego roll he does suffer the penalty, if he fails he over thinks it and fluffs it.
Or as a Stat you could even use +5 Int (not for maths or maths related tasks) +1/4 limitation or whatever., or use activation , or burn out.
Certainly, by adding the word complicated maths problems (14- or higher) you can tailor the modeling.