I agree that pet lambs are noisy which is why we haven't had any for many years
I have never used creep feed for lambs, just mothers milk and grass, hay and a very little 'Tup and Lamb' coarse mix when the snow's lying. Are your lambs going to remain pets or are you fattening them? 'Pet lambs' is a confusing term as it can mean pets or it can mean bottle fed lambs. Lambs which are not for breeding or for meat will not need as much creep feed as those being fattened quickly - you don't want true pets to get fat. For eating, I don't really fancy meat which has been grain fed; I like my meat to have been raised on grass and browse alone. Apologies if these are true pets (cover their ears). Yes, clover is good and tasty.
Your garden grass if nice and naturally green ie not overfed with artificial fertilisers should be fine for casual grazing, but for fattening you would want a specific grazing mix. The sheep will usually graze whatever grass is present as it is a normal behaviour. Eating manufactured feeds is not. I haven't read your other posts so I don't know how old your lambs are.
For browsing the greenery in your garden, it's usually fine, but have you checked
very carefully that none of the shrubs and flowers are toxic
to sheep ?