I’m personally using G&W.
Considering Wolf’s only real nasty matchups are the rat family and maybe like the street fighters, G&W can provide a lot of help due to him winning against both rats, Also wins against both streets, G&W can also help against more iffy matchups like ROB or Luigi. In turn Wolf wins against pretty much all of G&W’s bad matchups, like Palutena and ZSS and Ike, and can also go even with Lucina and Chrom. While providing some good coverage for characters like Olimar and Richter. I personally found that these two and ROB fit together perfectly since they both can struggle with characters like shulk or cloud, ROB doesnt struggle as badly against them. Plus if Wolf is against a Snake main, G&W wins against snake which going G&W can alleviate this problem