Since 2002 I have worked on all three USAF bombers, mostly on, but some off. When I started there were 90ish B-1's, that within 6 months became 67, 21 B-2's, and 76 B-52's. Today that stands at 44 B-1's, 19 B-2's, 76 B-52's. The B-1's weapons bays really limit it, also, it hasn't been a nuclear asset this millennium. If push comes to shove, the B-1 with all of its "throw weight" is actually the same as the Raider because the 3 bomb bays are all too short to carry what the B-52. B-2 and B-21 can carry in their bays (if we're talking, heavy, hypersonic weapons). The B-1 can move a bulkhead, which allows it to put a tank in the very shortened forward bay and carry the same as a BUFF/Raider in the "long bay" and small stuff/big fuel tank in the aft bay. External changes that, but there are treaties that have neutered that capability. Granted, the Bone carries 24 GBU-31 which gives it a higher "throw weight", but just because it carries that many, doesn't mean that a B-2 or B-52 can't have a single pass salvo that's a higher number.
Anyhow, 67+21 = 88 < 100 and 44+19 = 63 << 100. One hundred is a significant upgrade, anything over that is very, very nice.
In a previous post I actually computed the number of DMPI's current and future force structure. It favors the future, even more so if they buy more than 100.