I agree Tim, yet here are some thoughts/observations from over the decades...

I think in this case getting longer timbers is probably the much better plane, as they really aren't overly long...Not like a 40 tie beam or an 80 rafter plate, both of which are hard to work on and transport effectively or fiscally ($) easy to logistically manage either.

It does always "seems" faster in short view of this game to have full stock timber...yet perhaps the big picture would reveal more?

When we step back and really consider big stuff above 8x8 (these I think Brent said are 10x10) there is something there to think about. When we have truly examined all the logistics of log acquisition, transport, human ergonomics of lifting, moving, rolling, etc. the aspects of "splicing" starts to reveal perhaps a better path, as a smaller timber size...sometimes...may well rule out over using larger stock, or at minimum it works out pretty even.

As for strength, these joints evolved over millenia to try and incorporate as much "regained" strength" as possible...yet...I do agree they, on there own, no mater how well executed are going to be of lesser strength than a full natural timber. I would like to, however, suggest a few observations to the contrary or alternative of this.

I think when we state things like that...again we are loosing perspective of the larger picture. If we don't cut any joints in a cant (ie timber) it is strong, yet we wouldn't have a timber frame without those joints we cut. Placing joinery of all types...including splices...in the logistically correct spots they need to be is the..."art"...we practice. So adding a well planned, laid-out, cut splice to a column/post isn't really that much more deleterious...overall...than any other joints per se that we must cut...

I would also close with a very important aspect of this recommendation thus left out...glue. When this is added back into the equation for a splicing joint, we can usually not only regain complete strength back, but often (and these joints are heavily tested and even have competitions around them in japan) end up with a timber that would fail outside the area of the now "cut and glued" joint, just as rope breaks outside the knot rather than at it...

One added incentive...If after all the tally is in and it reveals a cost that is about 50/50 either way...I say lets pay ourselves for cutting neat joints and using joinery to solve our timber framing challenges...not just getting the biggest sticks we can...

Just some additional food for thought...ultimately do what feels right to you and the client with blessing from history's lessons of past timber frames...