As a retired RMS Clk, with 22 years experience, maybe I can offer some insight for you - YOU, of course, need to make the decision.
For 15 years I was an Adm Clk (831), dealing with Human Resources issues, amongst other operational administrative tasks. For 7 years I was an RMS Clk (836) - dealing with Human Resources, operational admin, and Finance. This state of affairs was brought about by the amalgamation of three trades into one. The three were:
631 - CEP Tech
831 - Adm Clk
841 - Fin Clk
The latter two were by far the largest, which is why the new trade (RMS) was assigned the MOC 836 - you'll note that 836 is precisely halfway between 831 and 841.
It's interesting to note that prior to amalgamation I was part of a staff check of Sr NCOs within the Adm Clk (831) trade, which recommended SPLITTING the trade into 3 distinct trades - Record, Releases, Operations - I would have fit comfortably into the Operations profile. The reason this recommendation was made was because of the dizzying breadth of expertise demanded of then Adm Clks - we were expected to be "experts" in far too many esoteric areas. Instead, the grown ups decided to create a trade that actually BROADENED the scope of the trade, leading to much confusion and dissatisfaction both within the trade, and within the trades we supported.
'Nuff history. How does this apply to YOUR situation?? Well, if you decide to join as an RMS Clk, there is NO GUARANTEE that you will be working in the finance world - you may end up in the HR world, or some other role supporting operations - nothing wrong with either place - but it WOULDN'T be Finance.
The choice of becoming an NCM first, then CFRing to Log(Fin) Officer is perhaps appealing, it enables you to get "hands on", prior to becoming a policy maker. I would caution you thus, however, in my experience, CFR officers were either OUTSTANDING or ABYSMAL officers. There didn't seem to be a middle ground where they were just "OK".
The outstanding ones seemed to be able to assimilate their prior hands on experience and know what was "doable" and what was not. They knew what their troops were capable of (even when the troops themselves did not), and were able to demand and receive the best from those troops. They were (and I imagine still are) amazing people - unfortunately, they seem to have been in the minority of CFRs that I met over my career.
The abysmal ones were of two sorts - those who CFRd from the Junior Ranks, and saw their new position as an opportunity for "pay back" on Sr NCOs/WOs, and those who CFRd from Sr NCO/WO rank and never forgot it - although they were wearing officer ranks, they continued to attempt to perform the Sr NCO/WO function - not a great way to run an Army.
So - if you are willing to take the chance of NOT being employed in a "hard finance" slot, and then take your chances regarding which type of officer you'll turn out to be, then enrol as an RMS Clk. IFF, on the other hand, finance is your hearts desire (and judging by your qualifications and statements made in your original posting), then I strongly suggest you listen to your Career Counsellor (is that what they call recruiters these days??), and wait for the Log(Fin) slot to come open for you.
Again - it's YOUR decision, but don't make the mistake of thinking that Jr Ranks, Sr NCO/WOs, and Officers are different "levels" on the same continuum. That may hold true for Jr Ranks and Sr NCO/WOs - to a certain extent - but an Officer is NOT simply a tradesmen with a university degree - their function is different - and the transition from OR to Offr is fraught with difficulties.
Good luck to you - no matter what your decision I'm confident you will find the military and extremely rewarding career - I know I did.