You have the right to discharge your attorney and substitute another even without cause. That attorney still has the right to be paid, unless they were fired for cause. If this is a contingency fee case, the outgoing attorney has the right to claim a lien on any recovery and unless both lawyers agree, The Court will decide how to allocate the attorneys fees between the outgoing and incoming attorneys.
If your attorney amends the Summons and Complaint to add another party--and as you say, adds the wrong party, only that party will be entitled to a dismissal. However, the fact that you were blaming another party who was dismissed may raise other issues which possibly could be used against you.
You are always free to change lawyers but I suggest you try to have an office consultation first to try and get on the same page.
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It is your case. If you wish to change lawyers, then you can.
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