Both Mr Percival and Mr Sutherland predicted smaller directly authorised firms would be the ones which would struggle to meet the demands of Mifid II's product governance rules.
And some of the largest networks in the country said they had attempted to help their advisers comply - though they did not directly respond on whether this had translated into actual compliance.
Stefan Fura, director of Furnley House Wealth Management, said: "I can only speak for my own firm and we are comfortable with the rules. At the heart of product governance is making sure the needs of your clients are being met by the products.
"To be compliant, that is the sort of stuff you need to be doing. It shouldn't be a particularly complex thing provided you understand your clients."
Caroline Bradley, group risk and regulatory director at Tenet, said: "Tenet has assessed the product governance rules against its own internal processes for panel management and are confident that these processes meet the requirements.
"In terms of our appointed representatives, we have provided them with guidance around client segmentation and will pick up on their adherence to these rules via field audit visits."
A spokesman for Intrinsic said: "For Intrinsic’s restricted advisers they choose from a panel of products and providers that are pre-researched by Intrinsic. To ensure the suitability of the panel we follow the rules of [product governance] and consider what products and providers are appropriate for the target market identified.
"Our restricted advisers can choose from a wider solution base if the restricted suite of solutions does not meet a particular customer’s needs. In those instances advisers must clearly document why the advice is appropriate in suitability reports. In annual client reviews, advisers need to evidence the recommendations are still appropriate.
"Independent advisers within the network will need to consider the suitability, as outlined above, but also follow our whole of market research requirements."
A spokesman for Openwork said: "As a national network, Openwork maintains a central suitability framework that all its advisers use when formulating individual client solutions.
"As part of our Mifid II implementation we reviewed all salient information available from our product provider partners to consider each target market and, for investment products, the alignment between their risk profiles and our own risk assessment tools."
The FCA declined to comment.