Golden Promise is the base malt for my house APA along with 4.4% light crystal (95EBC). That is a nice combo for an apa on the refreshing end of the spectrum. For my big IPA I use 100% gladfields american ale. But my porter has 6 malts and my session "American ESB" or what was once Earles Rogers clone has 5 malts. Horses for courses. As long as there is a reason for that malt then it's fine. If there is any rule of thumb it should be to ask yourself what is this malt doing to the beer? If you can't answer that then leave it out. I like to start either with a simple malt bill of my own concoction or a proven winner recipe and tweak from there. usually one malt at a time. I like to think of designing a beer as a tastiness hyper-surface. Move in different directions across the domain of possibility. See if you can find a path towards a local taste maxima because you're unlikely to find one by stabbing in the dark.