I say if you can do 2 x per week for each body part, with reduced volume then thats the best imo. 3x per week is pushing it without adequate programming, especially if that will lead to you underlifting on other muscle groups. If you do three days for chest then expect to do 3 days for back. In this case I might be best to do a Push/Pull/Leg split x 2 per week which may or may not be too much depending on volume/ intensity etc. Or even Upper/lower Upper/lower Upper/ Lower.
In any case, whether or not someone is over training cannot be determined simply by the amount of days training a certain body part. 3x per week tells us nothing considering it may just be 1 set of bench x 3 reps minimal effort x 3 days per week for all we know. People will have a better idea when someone writes up a prgramme with volume, intensity and muscle groups/ movements trained as too if this program has the potential to cause overtraining.
Its similar to asking, do you think 3000 brushstrokes is too much to paint my bathroom? How can we know unless given the dimenons of said bathroom and size of the brush. The more variables and information given, the more informative the answer