Lemon thyme apparently goes well with pork and chicken (the lighter meats)
For Beef & Lamb I go with common or garden thyme.
Cottage pie for me has to have loads of thyme and Worcestershire sauce ( the Worcs sauce has to be from Lea & Perrins from the Black country it's the best and I got fam there too)!
My ultimate Cottage pie is made with rump steak and sliced very, very fine & as close to mince as you can slice it but it still has texture.
I don't eat spuds anymore so it's slice sweet potatoes sliced cooked till soft and then on a baking sheet liberally sprinkled with strong or oak smoked cheddar served with runner beans top with a knob of butter!
I have a few Belfast/butlers sinks in my garden with thyme in them with gravel/stone on top of the soil, I never water them and never feed them and they keep going, they like it tough.
I prefer compact thyme to trailing (prone/prostrate) thyme but if I had the land it would be everywhere and all varieties and maybe even some lemon thyme if I had to lol
On a totally different tip here is a site you may like all about lavender -
http://everything-lavender.com/index.html