really depends more on your team build. if you're team is strike heavy, go with frieza. if your team is blast heavy, go with black goku.
another thing to consider is the number of stars you have each one at. if one is at 4 or 6 stars while the other is at 3 or less, there's a sizable gap in base stats that could make up for an outlier toolkit.
lastly, frieza deals 15% extra damage to frieza force characters so it could be useful if you face a lot of those. that group includes SP red broly, SP green vegeta, etc.
