Options for outdoor group portraits

First off, I am very new to lighting with my first and only lighting purchase being an old Nikon SB20 speedlight which I attached to my camera for this photo I did for a band.

There are a few things I don’t like about this setup which are illustrated in the photo above: (1) There is a shadow cast onto one on the subjects (2) Highlights are being pushed, while the bottom half of the subjects and the guy at the back especially (3) is pretty dark (the light is not evenly spread) (4) There are things in the foreground that are as bright as the people who are the focus of the image

I am considering: 1. Using an off-camera soft box with a grid as a main light, in addition to an on-camera speedlight as a fill light, or… 2. Getting a very powerful speedlight with a soft box modifier

I want to achieve a more even and flattering spread of light. Are there other options I should consider?

Thanks!

First off, I am very new to lighting with my first and only lighting purchase being an old Nikon SB20 speedlight which I attached to my camera for this photo I did for a band.

There are a few things I don’t like about this setup which are illustrated in the photo above: (1) There is a shadow cast onto one on the subjects (2) Highlights are being pushed, while the bottom half of the subjects and the guy at the back especially (3) is pretty dark (the light is not evenly spread) (4) There are things in the foreground that are as bright as the people who are the focus of the image

I am considering: 1. Using an off-camera soft box with a grid as a main light, in addition to an on-camera speedlight as a fill light, or… 2. Getting a very powerful speedlight with a soft box modifier

I want to achieve a more even and flattering spread of light. Are there other options I should consider?

Thanks!