Parallel charger circuits
Short answer: Putting power supplies in parallel is rarely a good idea. 

Why? 

Because the power supplies will have slightly different output voltages, one will supply more, and one less. It is next to impossible to determine in advance how the current will be divided. 

About your circuit, clearly, it contradicts the product sheet of the charger. The charger has to be parallel to the battery and the load, not in series. 

The charger IC is programmed to a certain charging current, max 2A. This is only indirectly related to the supply current of the solar panels. If they can supply 4A, only 2A will be charged to the battey, the rest should be drawn by the load. If the load doesnt draw >2A at all times, problems may (will) arise.