I agree with most of those IDs. Front left looks like Crassula perfoliata (aka falcata) or a close relative. If that's what it is, the plant makes bright red flowers in summer and becomes a bug magnet at that time, so be vigilant.
As is often the case when they are in mixed plantings, the agave will take over the pot in relatively short order. I would separate it in the near future, perhaps in the spring. It will probably appreciate more light than the other plants anyway. It has a wonderful urn-like sculptural shape when allowed to grow freely, accented by those variegated borders.