RewriteRule (.*?[A-Z]+.*) /${tolower:$1} [R]
RewriteRule ^([^_]*)_([^_]*_.*) $1-$2 [N]
RewriteRule ^([^_]*)_([^_]*)$ /$1-$2 [L,R=301]

RewriteRule ^(.*)(?: |_)(.*)$ /$1-$2 [L,E=DASH:Y]

RewriteCond %{ENV:DASH} Y
RewriteRule ^([^ _]+)$ /$1 [L,R=301]

RewriteRule ^(.*?[A-Z].*) /${tolower:$1} [R]
RewriteRule ^([^_ ]*)[_ ](.*?[_ ].*) $1-$2 [N]
RewriteRule ^([^_ ]*)[_ ]([^_ ]*) /$1-$2 [L,R=301]