This is ED Engineer being out of date - these blueprints were reduced to G1 in 3.0 (because a blueprint which exists only at G3 doesn't work in the incremental model) and Olmanova and Tah have the same version.
I've not seen any statement from FD about how many rolls should be needed, other than a very vague "quickly improve". The news items just give the current level, not a target. But I don't think 300 is excessive.
I think in practice it's a hard thing to balance for Frontier. If the expectation was that just people dropping by and upgrading their modules would do it ... well, it rarely takes five rolls to max out a G1 blueprint, and most people probably don't need that many G1 modules - the major immediate use is for adding experimentals to things you've remote workshopped ... so 300 rolls on the same module would take quite some time to accumulate even over the entire community, to even see anything reach G2.
On the other hand, it's about half an hour's work for one person to just supply 300 rolls of materials to an engineer (not counting the collection, but this is all low grade stuff you can broker for, so that's pretty fast too). So if it only took 300 rolls to upgrade a module, we'd collectively have them all maxed out by the end of the month, and I think they intended them to last longer than that. We're currently up to about 4000 with another bigger test and hoping to get a bit more in before Thursday. At that sort of 1000-10000 level it'd be a pretty long-term project to upgrade everything, especially if G2->G3 is harder than G1->G2 etc ... but we could probably make some visible progress on something every week.
