If the length is the same as the pitman arm, I doubt it would be any problem. The curve was probably designed to improve clearance. Looking at your pictures, I can see that this isn't a car built to factory specs, so I see no problem with it.
It is in fact slightly shorter, about 1/4." the curve lessens the clearance as it contacts the pan before the outboard part of the idler arm can get full swing. If it were straightened , it would have more clearance.
All the suspension is factory "Spec" as far as fit, form, function.