Ash'aris and Shia both prioritize reason over revelation regarding the Names and Attributes:
Shia rely on a book called: Peak of Eloquence (Nahj al-Balagha).
In this book, Imam Ali is said to have described Allah using philosophical terms.
The Shia problem is that the cosmological argument does not align with the words attributed to Imam Ali. They are therefore compelled to favour the Argument of the Truthful, because it is the one that corresponds to their text.
If Imam Ali truly said that, then we should listen to him, shouldn't we?
Yes, but it is historically impossible to prove that he actually said those words.
The book Nahj al-Balagha does contain some narrations that are also found in Sunni sources.
But the narrations that describe Allah in this way are found only in their books.
The most plausible scenario, given that Imam Ali lived in the 7th century, before Greek philosophy was translated into Arabic, is that Shia scholars of the 4th century, heavily influenced by Mu'tazilite kalam (itself influenced by Greek philosophy), inserted their own philosophical concepts into the texts and attributed them to Imam Ali to give them divine authority.
Furthermore, even assuming he possessed an extraordinary knowledge anticipating Greek philosophy, if he had delivered these philosophical sermons in public, no one would have understood what he was saying.
Among the Ash'aris, some do not use the cosmological argument but the Argument of the Truthful.
However, unlike the Shia who have the Nahj al-Balagha to justify this choice, the Ash'aris have no Sunni text that corresponds to this proof, which requires an additional intellectual effort from them to reconcile their philosophy with Sunni sources.