Id replace a frog with either a 2nd hourglass, a precognition, or shard of bravery. Probably not the last one cause you want shardless 
That one hourglas and two grabroids already need quite a lot time quanta and sometimes get in the way of each other. That's the main reason why there isn't a second hourglas or a precognition in it.
And about shard of bravery you already said it yourself.
