Dimension Brass can be used as perfectly with the smaller ensembles you are talking about. There are presets that let you run through different ensemble size matrices, you can design your own matrix, or even better, assign each solo instrument to discrete tracks in VEP for more control over divisi and ensemble arrangements. The library is meant to be used with all different configurations.
Not sure how the crescendos will sound without the actual performance articulations. I believe you can sort of do what you want with the APP sequencer in VIP 2, though again, not sure how this will sound. (I believe the APP presets assume you have the articualtions, so you would have to program your own.) Someone else with more experience re crescendo/diminuendo techniques may want to jump in here.
The chamber strings in SE and the DVD collection are the same (short of the full complement of articulations), no? Divisi of course would require having different size ensembles taking different parts instead of repeating the same full ensemble per note as you would get even with emulating 1st and 2nd violins,etc.; this is esp noticable in polyphonic passages. What you can get is the appearance of Violins 1 and 2 etc. by way of eq, filtering, and other means. There is also a way of doing it with impulses. But phasing would occur if there is an offset; here you would just have redundancy of libraries (so whay not just use your DVD collection if that's what you intend to buy) and emulate a 1st and 2nd VN arrangement?
Not sure what your needs are, but you may want to consider getting orchestral strings and/or appassionata and perhaps use the chambers that come with SE/Plus standard and extended, if that helps with your decision re Woodwinds 1 vs. SE/Plus (you get a lot of woodwinds with the SE bundle.) RE the latter, definitely get the extended libraries for both SE and Plus so you cover many articulations of solo and chamber strings (in other words, get the bundle). I have all the strings and I can tell you that the chambers sound great. I esp like the con sordinos (in which case, you would need chamber strings 2 dvd), but orchestral would seem (to me) to be the most useful across the board. Again, I don't know what your needs are. Appassionata are fantastic, though lack some important articulations. I've found that all VSL strings work well in non-orchestral genres.
Finally, I'm not sure if this works well, but a 1st and 2nd violins arrangment might be attainable using orchestral and chamber strings respectively (also layering with solo strings works nicely to get a more authentic, less anemic feel). Others might want to jump in with their own suggestions as they may be more experienced with arrangement techniques.
As always, you might want to contact VSL directly with some of these questions. They obviously know more than I do and will help you with the best purchase decision. Others on the forum should help as well. A plurality of opinions is always best. There are a few things I may be wrong about here :)
HTH
Mike