I just thougth since credits are used up before gc, and the collum for specialists comes before elites it might be wise to micro mannage by training elites before specialists.
Now I don't know for sure if this is how it would work, but given a senario where you have 500 soldiers and 250 credits and want to train 250 specialists and 250 elites, if you try to train all 500 at once I believe you could risk spending your credits on the specialists and not beeing able to fully train the number of elites, or atleast spending much more monney than intended because you'll have to pay for the elites and not the specialists.
Based on my experience if you got 100 acres and click dubble cost and you can not afford this you'll get the numbers of buildings you could afford with dubble cost build from the top, which means you'll not be getting those 20 Dungeons cause you could only afford the 80 buildings from the higher collums, if training troops are the same you'll need to start training elites first or lose a lot of resurces, and you might not even notice if the number is small and you got plenty of gc.