I've obtained all four unique blunderblusses but i have no clue which ones are optimized for my build(Streetfighter/Helswalker). 
It seems i can divide em into two categories such as 
  
Single target - Xefa, Kitchen stove 
Multi target- Hand mortar, Fire in the hole 
  
Do i have to equip as weapon set 1(single) set 2(multi) and keep switching throughout the battle? 
  
Any words would be appreciated. Thanks.