We can easily define argument list by fzf.vim.
I will show my configuration.
Please refer to this article for argument list.

Vim

Configuration is below.

function! SetArgumentListByFzf()
    " Clear argument list
    execute "%argdelete"
    " Run fzf with preview and select files.
    " Run argadd command passing seleted files as argument.
    call fzf#run(fzf#vim#with_preview(fzf#wrap({'sink': 'argadd', 'options': '--multi' })))
endfunction

Demo

Now, we can easily set argument list.