I cannot tell you how frustrated I am that Krennic and Deathtrooper are already being taken out of the shard shop. They've been farmable there for what, 2 weeks? And now they're unfarmable again. What the hell? I've been putting everything I have into the shard shop and I've only got Krennic at 5*. How am I supposed to get these characters now? Either make them farmable in other areas or leave them in the shard shop.
I am so mad too, Baze and K2 were on the Shard Shop a very Looooong time
Krennic is farmable on node 9-D LS hard battles
Deathtrooper is farmable on node 8-A Cantina battles
So you can't say they are not farmable, however I have heard the RNG drop rate for DT is really poor and for Krennic he also has a poor drop rate - especially at the cost of 20 points of energy for your 3 attempts - more if you refresh. So farming them will certainly be difficult.
Having said that - the cost for their top amount of shards from the shard shop was like 6k shard shop currency, which was equally insane in my opinion. So, they were hard to get and they are still hard to get, lol