This paper investigates the ability to provide improved Reliability of TMR systems at comparable area and time cost using design diversity. Namely, we evaluate multiple implementations of the same functional design using a repository of methods: Templates, Case-Based, Inverted-Output, and NAND/NOR-Based methods. The design methods are tested on multiple benchmark circuits in different TMR setups for each of which design diversity and fault tolerance are examined. The results show that extensive design diversity can be achieved at design-time using one or a combination of these methods, and verifies the increased fault-tolerance of TMR-based systems with diverse designs in multiple failure modes at run-time. Moreover, results indicate that improved system fault-tolerance can be achieved using designs from different classes of design techniques, rather than using variations of the same design method without incurring a run-time expense.