You absolutely can have too much. Too much leads to lack of playing time for players who deserve more. That leads to chemistry problems.
This link from Scientific American explains it pretty well, and there is plenty of evidence out there to prove that too much talent on one team is detrimental.
https://www.scientificamerican.com/article/the-surprising-problem-of-too-much-talent/
Why is too much talent a bad thing? Think teamwork. In many endeavors, success requires collaborative, cooperative work towards a goal that is
beyond the capability of any one individual. When a team roster is flooded with individual talent, pursuit of personal star status may prevent the attainment of team goals. The basketball player chasing a point record, for example, may cost the team by taking risky shots instead of passing to a teammate who is open and ready to score.
When JBo and Nunge come back, along with, God willing, Garza and a healthy P-Mac, this team will be absolutely loaded. Additional talent isn't going to help. Chemistry and teamwork is the key.
A little defense wouldn't hurt, either.