Law firms will happily take on as much work as you need if you’re happy to pay for it!
However, since this is typically an expensive option, it should be used deliberately rather than reactively, when the circumstances point towards a law firm as the best solution e.g.
jurisdiction: where expertise/resource is required in jurisdictions and your team lacks local resource/knowledge;
specialism: where specialist legal knowledge is required (and it’s not an area where training/hiring a specialist internally would produce a better ROI);
firepower: where the work simply requires a level of resource your team does not have the resource to provide.
For (typically) higher-volume, lower-value/complexity work, another option might be to outsource to an alternative service provider (ALSP). This can provide a cost-effective way to free up capacity for higher value/more strategic work.