There are many synonyms that can be used instead of "went in with" depending on the context and the tone of the sentence. Some possible choices include "entered into," "joined forces," "aligned with," "collaborated," "associated with," "partnered with," "teamed up with," "united with," "connected with," "merged with," and "cooperated with." These terms all convey a sense of working together or joining forces in some way. It's important to choose a synonym that fits the specific meaning and nuances of the sentence to ensure clarity and effective communication.