Seconding brody & SpaceCadet. I think that the best pregames are the ones where your team is slightly better than the opposing team. The benefit I often see by getting the "slightly better than them" type of pregames is that they give some of the clearest insights on what adjustments your team needs to make while also boosting everyone’s spirits a bit.
If your team gets vaporized by a way better team in the pregame, chances are that the opposing team exploited many different weaknesses simultaneously. Since there's not a lot of time to digest wtf happened, there's no way your team is going to fix all of it between the pregame and the official. This can lead to your team overcorrecting in the following game, e.g. playing too passively or too aggressively, abandoning legit strategies, etc. On the other end of the spectrum, if your team vaporizes a way worse team in the pregame, this can solidify bad habits and may not lead to any insights at all.
In short, pregames where your team goes, say, 5-3 are the Goldilocks. You get your warmup in, you get the nice confidence boost and you probably catch a couple of things that you could be doing better, too.