I've extended this to 2 brigades of 2 Line regiments, each with attached grenadier company ready for detachment.
And a brigade of 2 Fusilier regiments, with the recently-completed Hanoverian battery.
In order to make up 2 full detached grenadier battalions, I have 2 stray companies of grenadiers - the regiments they are detached from are currently languishing in garrison, awaiting the first sniff of undercoat.
I debated internally whether to depict the grenadiers in bearskin (a la AWI) or mitre (per SYW), but the existence of the fusiliers in mitre, together with (to be honest) a horde of cheap bearskin-clad Foundry AWI grenadiers on eBay, rather tilted the decision. In an ideal world I would have both available ... but then, I would also have the whole British army represented on a 1:10 figure scale, painted and ready for action, in an ideal world.
*purchased already painted, quite splendidly, on eBay. I regret that I've forgotten the vendor, who was I think moving out of the period, but they were beautifully & sturdily presented.