The phrase "are mostly aiming to" is correct and usable in written English.
It can be used when discussing the primary goals or objectives of a group or individual, indicating that these goals are not absolute but rather a general focus.
Example: "The researchers are mostly aiming to improve the efficiency of renewable energy sources in their latest project."
Alternatives: "are primarily seeking to" or "are generally focused on".
Nowadays even the best private-equity firms are mostly aiming to achieve annual returns of only 15-20% on their capital, down from 20-25% in the 1990s and over 30% in the 1980s though in the buy-out business they still hope at least to double their money on every investment.
For another, microconsoles are mostly aiming to be cheap – both in hardware and games – and so the expectation that they should be powerful is a stretch.
These ingredients are mostly aiming to absorb or rinse away any oil and dirt.
Thus, validation of cleaning of contact surfaces is mostly aimed to demonstrate that microbiological contamination is kept within the proper limits, depending on the desired classification level (EU et al. 2017b).
The current crop of sensor-driven wearables are mostly aimed at quantified selfers who want to geek out over activity or fitness data.
They are mostly aimed at deferring the economic pain, and offering treats to woo Republicans who are wary of an enterprise that, along with health-care reform, has been one of Barack Obama's most cherished goals.
Previous studies that have tried to evaluate the taxi market are mostly aimed at providing policy advice.
The current emoji are mostly aimed at social activities, and there's very little to represent inner states of mind or 'alone' activities.
Since tax credits are mostly aimed at low-income people who pay tiny amounts in taxes, the impact will be to exempt those people from paying any taxes.
Yet these packages are mostly aimed at hard-core fans or those who still yearn for physical product.
China's government regularly announces corruption crackdowns that are mostly aimed at snaring government officials who accept bribes.
