Is there a difference between borrowing against shares from Bank Albilad and AlAhli Bank, given that the latter offers a lower interest rate?

Such matters should be referred to specialized scholars, as they are knowledgeable about the state of banks and their transactions. The role of a fatwa (definition) website is to state the conditions that, if met, permit engaging in tawarruq or murabaha, and to rule on the presented contract formula. However, endorsing a specific bank or ruling on all its transactions is not within the site's purview. A bank's purchase of shares and their sale to a client who orders them is not a loan; rather, these are financing transactions. Contracts should be named by their proper names, because borrowing with interest is riba (usury), while selling for profit is permissible. Allah Almighty says: "And Allah has permitted trade and forbidden riba."