Is this set-up o.k. or am I asking for trouble with the system "down the road"?????
If you live where I do you are in trouble up and down the road. So the answer to your question is: it depends.
If you review evaporator coil specification you will immediately notice that the same physical piece of heat-exchange hardware is used over a range of capacities depending on the fixed orifice or TXV supplying the refrigerant. The vendor of the compressor will have a listing of appropriate evaporator hardware it approves for the unit. This is indeed important if your warranty matters to you it and thus would be prudent to stay within those models.
On unique situations "other" evaporators may be authorized by the vendor’s local rep (I've known this to happen, but have not personally gone this route).
The word "OK" needs to be clarified, as does "down the road" understood? What would better serve your perceived purpose is to give the actual vendor and model numbers in question. There are many talented folks on this forum that would then be empowered to provide meaningful dialog.
That said, also of significant importance is the diameters of the liquid and suction line, the vertical lift from the compressor to the evaporator and how many pounds of air the air handler is configured to move over the evaporator’s surface.
Be certain that you understand the difference between sensible heat verses latent heat, since the methods for giving evaporator capacities also vary. A “4-ton” evaporator may be grossly undersized if mated with a 4-ton compressor in an extremely “dry” climate such as AZ since the coil may be an aggregate of 3-tons of sensible and 1-ton latent (not uncommon). In Arizona, sensible is the entire ball game, understood?
Trust that you’ve master Psychometrics since it is paramount in sizing residential refrigeration units. Also of great merit is ACCA’s Manual “S” (highly recommend mastering the material contained within)
Finally deal with a company that has been in business as long as the warranty period and has a good reputation in your location. The skill and precision used in the installation may override all the aforementioned! Pay for talent, it may be your wisest choice of all.