The phrase "reach too far" describes a scenario where someone is overly ambitious and tries to achieve something that is beyond their capabilities. There are several synonyms for this phrase that can be used to convey the same message. The term "overambitious" suggests that the person is attempting to do something that is unrealistic or impractical. "Bite off more than one can chew" refers to taking on more than one can handle. "Stretch oneself thin" implies that someone is spreading themselves too thin and may not be able to cope with the demands of their situation. Another synonym is "overextend," indicating that someone has extended themselves beyond their limits. All of these terms convey a similar meaning to "reach too far".