I am having a hard time choosing a singular marja because I agree with particular marjas like sistani and khamenei on some topics but other marjas on another. I tried to find a solution and I came across this on Fadlullahs website.
“In taqleed, is it good enough to follow a particular jurist in certain matters and another in other matters?
A. Yes, it is permissible, provided that when you switch to another jurist in a particular matter, you should abide by his fatwa, especially when you know that changing your mind again would certainly entail committing a wrongdoing (mukhalafah). For example, if you have shifted to a jurist who is of the opinion that a given act is haraam, then changed course again to another jurist who sees it is wajib (an obligatory act of worship), you are not allowed to change again.”
Does this mean that fadlullah allows taking fatwas from multiple marjas? Or am I misunderstanding?

One should follow one marj’a and not switch based on what they consider to be reasonable or make sense. This is because the person is relying on that one jurist’s knowledge, experience and accurate derivation of the law. In fact, if one marj’a is known to be the most knowledgeable in all aspects then one should follow them solely given the confidence in their legal derivation