You can change lawyers halfway, because these are general agency contracts. If you are not satisfied with the lawyer, you can hire another lawyer.
Criminal procedure law
Article 45 During the trial, the defendant may refuse the defender to continue to defend him, or entrust another defender to defend him.
Article 33 A criminal suspect or defendant may, in addition to exercising the right of defense, entrust one or two persons as defenders. The following persons may be entrusted as defenders:
(1) lawyers;
(2) A person recommended by a people's organization or the unit to which the criminal suspect or defendant belongs;
(3) Guardians, relatives and friends of criminal suspects and defendants.
A person who has been sentenced to punishment according to law or deprived of or restricted personal freedom shall not act as a defender.
A person who has been dismissed from public office or has his lawyer's or notary's practice certificate revoked may not act as a defender, except the guardian or near relative of the criminal suspect or defendant.
If you plan to change lawyers in the middle of the lawsuit, you can come to legal advice.