Decreased signal strength: Splitting the signal between two boosters can weaken it for each. This might be counterproductive to your goal of strengthening the signal. and when the improper installation on donor antenna of the signal boosters,

if will decrease the signal strength. 

Complexity: Setting up and ensuring proper function of two boosters can be trickier than one. if the area you want to cover is not enought by using one signal booster, then suggest to use one higher power signal booster.

Potential interference:  Using multiple boosters in close proximity can lead to interference, negating any benefits.

There are better approaches to consider:

Using a single, stronger booster:  A well-chosen booster for your area and needs might be sufficient.

Optimizing antenna placement: The location of your antenna can significantly impact the signal strength. Try adjusting the placement of your existing antenna.

If you're unsure about the best course of action, consulting a signal booster expert（Ampplitec) can be helpful. They can assess your situation and recommend the most effective solution.