When I started playing with units that had the combined melee/combine range attack ability, I was generally confused about how to configure my attacks to be the most effective. If I want to take down a heavy, should I lump everyone into a single attack? It turns out, no, not always. It may even be different if you're benefiting from an extra dice for charging. If I want to use my Long Gunners to kill as many Iron Fang Pikemen in a turn, how many should I group up? What about against Fennblades? Actually, the answer is different for each.
Against a single target, it's a little more straight-forward than against multiple targets. We're just concerned about piling as much damage into one guy that typically has high armor.
For multiple targets, assuming your goal is take as many targets off of the table as you can, you also have to factor in the target's health.
The spreadsheet allows you to enter stats for the attacker and defender along with the configuration of the CRA/CMA. I sometimes refer to that as CXA. The results tell you how much damage to expect against a single target or how many models you're likely to kill in a single activation. Any number of attackers can be represented, up to 10. I'll probably need to increase that to allow for some of the unit attachments. We also don't take into account the slightly better stats of some of the officer attachments.
To use the spreadsheet:
After clicking on the link, select 'File->Make a Copy' to copy the file to your own Google Drive. Once there, you can make all the changes you like.
Link to the Spreadsheet