You will find some who will advise to stock northern ponds together if they are same size class. I put in BG and LMB same day. They were all 2-3". The bass won't reproduce the first year and maybe not the second. There were small BG all over the place the second year. First year, the bass were mostly wiping out FHM. By second year, the GSH were pretty well gone. They were eating pellets the whole time.
If your LMB are larger, you may want that gap in stocking to let the BG get going and have enough size to escape that maw. My BG grew fast enough that there have always been a good number big enough that no LMB could eat them. The first year, my LMB were mostly adding length. They remained slender until about 14". Then they started getting wider and the mouth got bigger and they started hitting mid-size BG. I have 1 lb BG now and I doubt I will ever have LMB that can take them. As I understand it, that is what will mess up your plan if LMB get big mouths before a portion of the BG are too big to eat.