if you want to upgrade, your direction should give you a significant change from what you have now. There is not much to gain from getting the same speaker model with only a dent of difference. 9.1 is a BS speaker, shifting to a FS wharfe will not give your higher gain considering that your setting for the speakers would most likely be small anyway. In the home theater setting, the midbass part is hardly noticeable unless you are using speakers with 8 inches and up woofers.
If you have enough budget, get a different brand of speaker so you really can hear significant difference, the Monitor Audio BX5 and BXLCR can be an option, SVS too has a lot of options for you and so is Polk Audio.
You need not worry about your surround speakers as in case you want to save up, you can keep the 9.1 and dfs. Timber matching is very important but for non sophisticated ears,it hardly matter, di rin masyadong mapapansin ang kawalan ng timber matching in case ibang brand na ang front at center speaker mo. You only have two types of surround, the surround speaker and the surround back speaker. your 9 dfs is a dipole speaker, which performs very well if installed at the side wall along the line of your seating position. your 9.1 can be used as surround back, which most of the time is direct radiating or monopole(one direction only),
if your room is not that huge, you will hardly benefit from a 7.1 set up, the DFS would more than suffice, bihirang bihira naman ang movies na 7.1 ang encryption eh
I used Yamaha with wharfes, ok naman, i used wharfes diamond 9.1, 9.5, 9cs, 9cm with Onkyo ok din naman, issue lang with wharfes medyo bitin sa high frequency pero madami namang tao gusto ang ganito
