If I do not take the planets leading to the shard (or from the shard to my HW, which is the same thing
), I do pretty much the same. I however do send in the fleet to cover them (cloakers & shard).
Not sure if the AI would have picked up but I've seen it happen too often that the AI rushes towards the location of the shard (which is on the move), uncloack the cloakers by getting close, than stomp them and still end up chasing the shard. So the fleet will be there to make sure the AI simply wont get close in the first place.
Do have to admit that I normally try to get the shard to my HW with 100% health, makes me feel all warm inside