Tsenis,
I agree it is easy to jump to conclusions and it does need verification. If it is indeed Krasnoarmeysk it should be easy for the person on Twitter making the claim to photograph the exact location seen with billboard, road etc.
Other claims have been made about the transporter truck.
Looks like the same transporter truck with Buk on back? Claimed to have been seen in a rebel convoy that entered Snizhne.
Claimed to have been seen in convoy with a separatist truck although there doesn't seem to be any footage of the two together? The milita truck appears to be one of the separatist "Mad Max" type conversions?
Max Max truck conversions at 0:26, 01:00 and in convoy at 02:46