Under there the ECS is also a 3+1 phase and I have no idea of the quality. ECS boards have been known to be particularly shoddy on the quality (outside VRM setup).
If you're taking on a 6 core at least pair it with a reliable 4+1 phase setup. More is better yet, esp. if you intend to make use of those 6 cores to their full extent frequently. More phases = less heat/stress per phase = cooler board = better efficiency and reliability.
Having an 8-pin connector is not an indication of whether VRM systems are better than not. Look at the MSI 870A-G54. It is an 8-pin connector board and at the same time it is the most VRM failure-prone board in existence. Meanwhile, the robust ASUS M4A79XTD EVO has a 4-pin connector supplying an 8+2 phase system. It's a very robust board with no recorded failures or throttling events on high TDP processors.