Right now, Death Globe Bombardiers feel a little too niche to be worth bringing. 9/10 times Rattling gunners are simply a better option for most engagements. If you made Death Globe Bombardiers and Poison Wind Globadiers better in melee however, you'd be giving them a distinct role as a melee/ranged infantry hybrid. Both units already have good armor and health per model in comparison to the rest of the roster, all they really need is a boost to their melee damage and attack to make them more useful in close quarters. From a lore perspective, you could make an argument that they cover their blades in warpstone-based mutagens to increase their lethality. In game terms I think this could transfer over to a 5-9 bonus versus infantry. It would makes sense. as an unit with a short ranged weapon like the death globe, should be trained and equipped to finish off enemies from close quarters after the initial volley. But those are just my thoughts.