No college team ever could beat any modern pro team imo. The size / strength / experience difference is just far too great. If any team kept it with 30 would be a surprise. Most games being about 45-0. If you matched up today's powerhouses vs teams from the early 70s and earlier, there could be some close games, when the players sizes and strength would be more evenly matched up. But modern high tempo offenses could really wreak havoc on old school style defenses. But if you went back to the days when wishbone ruled the nfl, that might be hard to prepare for, like a game against a grown ass man Georgia tech squad. It would actually be really interesting to watch.