I agree with all of your comments. It seems like the consulting firm just used a bunch of different graphs for variety, rather than using the types of graphs that would show the data most effectively. Besides the meaningless variety, their graphs contain several design problems, such as unnecessary 3D, incorrectly used stacked bars, and data points on the lines that are completely unbalanced in salience (the invisible white data points on the pink lines are especially silly).
The best design for this dashboard will depend on what your organization wants to focus on. Are you mostly interested in seeing how each of the KPIs have changed over the past three months (or some other period of time)? As it is, each of the months is equally prominent. If this is your goal, line graphs are probably your best bet. If all of the assets in each graph share the same target, you could indicate this with a reference line or reference fill area so it’s easy to see which assets have surpassed the target. If each of the assets has a separate target, consider breaking the lines into separate small multiples, each with their own reference line or fill. The dashboard is fairly data sparse at this point, so you should have room.
On the other hand, it’s likely that you’re most interested in the current value and you just want to see the other months to get a sense of history. If this is the case, I recommend using a combination of bullet graphs and sparklines. The bullet graphs will draw people’s attention to the current values and they’ll be able to easily compare them to the targets and assess their performance, while the sparklines will give people a basic sense of history. Stephen often uses this combination in his dashboards because it allows you to fit so much information to a very small place. For information on designing the bullet graphs for your “lower is better” values, take a look at this blog entry
that Stephen wrote a few years back.
Regardless of whether line graphs or bullet graphs and sparklines serve your purpose better, you should also consider whether people care more about the actual values or care more about how they differ from the targets. If people are mostly interested in seeing how the values compare to the targets, consider visualizing that directly. For instance, if you use line graphs, instead of using one line for the value and one line for the target, graph a single line that represents the percentage that the value differs from the target.