@dostovel I don’t know about Modeling reels for sure, but for Animation reels 1 min 30 secs is considered the ideal length. 1 minute or less is a student reel who haven’t got much work yet, anything longer than 2 minutes suggests you can’t choose your best works and recruiters loose their interest because it’s taking too long…
Also for animation reels they advice to start with your best shot (to grab attention) and to end with your second best shot (to leave the receivers with a good impression, wanting to see more). Might work great in terms of best model & second best model as well.
Additionally, only include your best work. Your reel is only as strong as your weakest shot (weakest model), so make sure the stuff in between is professional quality as well.
Hope this helps..