In theory, yes
(From a certain point of view, we already have two hearts. But let's ignore that sophistry.)
Naively thinking, two (or even three or four) hearts might indeed have a significant advantage in terms of blood pressure.
There would almost certainly be no advantages in terms of redundancy.
Coronary heart disease as well as mechanical wear on valves would arguably affect both hearts in the same way, so there is little to gain. A trauma destroying one heart would likely either cause death by exsanguination (puncturing trauma) or would have a good chance of destroying the second heart as well (blunt trauma).
In any case, the backup heart would not be very well-adapted to suddenly having to handle twice the load, either.
However, the pressure advantage remains, if you ignore the practical "implementation problems":
As it stands, the heart generates a short, extreme peak pressure during what we call systole (around 130mmHg on average, but quite possibly twice as much in some conditions) followed by a period of no pressure at all.
Ironically, the heart itself needs blood to survive, too, and blood will only flow through the coronary arteries during the diastole. So, someone, somehow, has to make sure this works. Blood generally has to keep flowing in a kind of steady way.
To add to this, certain organs -- kidneys most notably, but also the brain -- require a certain minimum pressure and a certain average pressure (of around 70mmHg if I recall correctly) or they will cease to function. This is one of the causes that may e.g. result in the phenomenon known as "shock kidney".
These requirements are a considerable challenge to the arteries which are responsible for keeping that beast running. They must be both muscular and elastic, they must be able to adapt to changing conditions rather quickly and invisibly (you have no idea how much work is necessary when you stand up, just so your brain won't suddenly stop working!), and they are subject to a lot of wear and tear and calcification.
Wouldn't it be nice if we could make the lives of our arteries a bit easier? It turns out we can.
Given two hearts which beat anti-synchronously (or even three hearts running in three-phase mode), in order to achieve the same average pressure, the peak pressure could be much lower. The pressure curve would naturally be much smoother, on a more even level. The problem of having to maintain a pressure minimum would magically go away.
This is comparable to an "ordinary" four-stroke car engine in comparison to a six-cylinder or an eight-cylinder, or to a "typical" motorbike engine with one or two cylinders on the other hand side. The "more cylinders" engine will always run a lot smoother, with less noise and vibrations (when assuming the same power, obviously a 10-15x more powerful motor will make more noise!), and with less overall tear and wear.
Now, the problem is getting two hearts to beat in sync, anti-synchronously. If they get out of sync, you will see more or less pronounced interference effects (as known e.g. in electrics or acustics). In the average case, you would have a sub-optimal pressure / blood flow. In the worst case, you would have the pressure waves add up, resulting in a pressure spike twice as high as anticipated. Unluckily, due to the nature of asynchronous waves interfering, that worst case is not just possible, but guaranteed to happen regularly.
Thus, you would have to build a system that guarantees that the hearts are, and stay, in sync. Rather than having their own SA node each, there would have to be a single SA node for both hearts, and a "delay circle" of sorts for one heart which delays the signal by exactly one half period length. Of course, the delay circle would have to be communicated from the SA node since it needs to adapt its delay with the heart rate.
That's a very complex system with a lot of logic, which is prone to failure. The two hearts would arguably need to be physically separate (rather than just doubling the number of chambers) in order to retain the "wear and tear" advantages. That would however place the SA node (which is a single point of failure) somewhere in between them, presumably in fatty tissue, making it again rather vulnerable to external injury.
If anything happens to this complex system, it all blows up.
The hearts that we currently use have as-dumb-as-can-be designs, which is what makes the design so ingenious. There are no "super clever" bits in them with a lot of synchronization and steering logic. It's membrane potentials spontaneously building up, and firing, and a few conducts and insulators that direct the wavefront in the desired shape. Yes, there are a few regulation mechanisms which can slightly moderate (but not substantially change) the function of certain parts in the conductive system, but all in all it's a hardwired, stubborn little thing that does exactly what it does during your entire life.
There is hardly anything that could go wrong, and this is a good thing. A heart rarely ever fails. You could say it happens on average once in a life.