"largely ad hoc" is a correct and common phrase in written English.
It is used to refer to something that is done or assembled without any real plan in place, often to solve a specific problem. For example, "We had to put together a plan to tackle the issue, so we created a largely ad hoc approach."
Even so, finding a mentor remains a largely ad hoc process.
Figures such as the policy review co-ordinator, Liam Byrne, would probably admit that the hydra-headed reviews, set up November in a largely ad hoc way, lacked coherence.
Previous reduction algorithms have been largely ad hoc in nature.
Many standards and provisions are still largely ad hoc.
Nonfunctional verification approaches, because of their inherent subjectivity ("what does it mean for a system to be modifiable?"), remain largely ad hoc and manual.
The vote, organised on a largely ad hoc basis with no clear control of authenticity of ballot papers or voter lists, could have serious consequences for Ukraine and relations between Moscow and the West.
This governing style was largely an ad hoc reaction to failure and crisis.
To date, planning has largely been ad hoc and influenced by external factors, with little regard for Aboriginal aspirations for the future.
For small molecules discovered in such screens, identifying the biological targets remains largely an ad hoc affair.
To date, the development of alcohol policy has largely been ad hoc and reactive, with subsequent policy relying on strategies that are ineffective but popular.[ 13, 15] For example, school-based education is an ineffective measure to reduce alcoholrelated harm but is nonetheless a very popular option with governments and their constituencies.
They are largely attitudinal and ad hoc.
