The phrase "are much more restrictive" is correct and usable in written English.
It can be used when comparing the level of restrictions or limitations imposed by different rules, regulations, or conditions.
Example: "The new policies are much more restrictive than the previous ones, limiting our options significantly."
Alternatives: "are significantly more limiting" or "are considerably more constraining".
As evidence of gadolinium retention after exposure continues to pile and taking into consideration immature foetal renal function, recommendations are much more restrictive.
Somewhere like Bogota, in comparison, the costs are much more restrictive.
For example, in the strictest case, we do not admit singleton reads in ISV, meaning the placement constraints are much more restrictive than for DSV.
Accordingly, the conditions for speciation through sexual selection are much more restrictive than the first models seemed to suggest (see also Arnegard and Kondrashov 2004).
The relative tolerance for the aspect ratio (AR) is much more restrictive (≤ 5.3%).
The agency's staff first proposed to set a price monitoring and mitigation formula that was much more restrictive than the one adopted today.
While the options were preliminary, they were much more restrictive than those offered by Mr. Davis today, and included the possibility of re-regulating markets.
However limiting and intellectually repressive parenthood may be in America, it's much more restrictive for mothers in traditionalist gender-segregated societies like Japan, Italy and Greece.
In addition to imposing immigration quotas, Switzerland is much more restrictive in granting asylum to refugees from places like Syria than many other European countries are.
It is possible for small satellites to hitch a ride along with big payloads, but that can be difficult to arrange and is much more restrictive than having a dedicated low-cost launch vehicle like White Knight Two.
With those guidelines, it is taking a page from Apple's playbook, by being much more restrictive about the glasses than it has been with other products, particularly its Android operating system for phones, and controlling the type of apps that developers build.
