Before delving in this matter, making note of this point is necessary that taqlid must take place in accordance with the standards and guidelines set for it; we mustn’t have presumptions for ourselves, and then set out to find a scholar who confirms them. Clearly, such cannot be called true taqlid.
As for your question, it is a bit vague, but we will address the different cases you might have meant:
1- If what you are asking is whether those ulema who don’t believe in the concept of Wilayah Faqih must change their viewpoints and support it, the answer is: If a faqih who is qualified for ijtihad, by observing all the principles and standards of jurisprudence, comes to a conclusion, no one can force him to change his mind. All that can be done is to challenge his viewpoint through the same principles and try to change his mind through ijtihadi logic.
The leader of the Islamic Revolution, Ayatullah Khamenei says in this regard: “If a person, through jurisprudence and argument, doesn’t come to a conclusion on the concept of Wilayah Faqih, he will be excused by Allah, but he mustn’t act in a way that leads to the disunity and conflict of the Islamic society.”
What we see from most of the great ulema who don’t believe in the concept of Wilayah Mutlaqah Faqih is that they don’t put fuel to the flames of conflict and confine their debates about this issue only to appropriate scholarly discussions.
2- Even if we assume that the concept of Wilayat Faqih is a theological one in which taqlid is not acceptable, and the followers of the respected maraje’ who don’t believe in it at all, or believe in it, but limit its scope, refer to these same maraje’ as Islamic experts and follow them in their opinions on this subject and don’t believe in it theoretically, they still must try to comply practically and mustn’t engage in actions that will hinder the Islamic society’s unity; the reason being that if a person denies a system of government or even stands up against it, he must have a better system in mind that he is aiming for.
Those who don’t care much for the marja’iyyah and taqlid, may support other forms of government that are utilized in the world today and present them as substitutions, but what can the motives of the followers of those maraje’ who aren't ready to establish governments themselves be for standing against and fighting the government of the Wali Faqih?
3- If you are asking about what those ulema, who totally accept the concept theoretically, but doubt about who it is identified with today, must do regarding the Wali Faqih:
If we say that every scholar and faqih who doesn’t believe that the current Wali Faqih should be Wali Faqih is free to act against the government’s regulations, great chaos and disorder will follow; there is always a possibility of a Wali Faqih having opposers from the class of the ulema.
Judging by the arrangements made by its constitution, it seems that the Islamic Republic, if it ever happens that a faqih(s) has objections to certain issues and demands that his case be looked into and dealt with, bears the capacity to accommodate and tend to them.