These garlic bulbs have the same genes as the "mother" bulb, and given time will usually grow into a nice sized bulb. If the bulb is a round with only a single clove, then it should grow into a nice bulb next year. If the bulb has multiple small cloves, then each clove should be planted separately and should grow into either a decent bulb with multiple cloves or a large round with a single clove, which in turn should become a nice bulb the following year.

It is a common misconception that small garlic cloves don't grow well and shouldn't be planted. Indeed, if you want to increase your stock fast, then you should replant as much as possible, even if they are only very small cloves (or topsets, or even the basal root end of a garlic clove). The fact is, that generally, if you plant a large clove, you will get a large bulb within one year, not that small bulbs are useless.

Good luck.