Hi @luisramos, welcome to the forum!
I don't think it's at all common for APM Server to have a coordinating ES node running locally.
APM Server is mostly just indexing data, and the few queries to ES it does make are cached. This is unlike Kibana, where queries to Elasticsearch are in the critical path and affect UI responsiveness.
We generally recommend that you position APM Server closer to the Agents to minimise time taken for agents to offload data. That doesn't preclude running a coordinating ES node, but I wouldn't expect it to make a significant difference.