Finding the right routes

I was talking to a friend of mine about this challenge the other day. It was a conversation about the route I was planning to take after I've completed the North Downs Way. But the friend asked me, if you're going South East to North West, why are you planning to go further south by going to Winchester and Salisbury, before turning northwards to Bath? Is that not wasted energy, time, money? 

So this got me thinking. (Yes, there was smoke...) Should I be a completist and endeavour to complete full National Trails before moving onto the next via connecting paths/ways/trails? Or should I concentrate more on getting further north? I've done some research and this is what I could possibly do if I'm not being completist:

I'd have to come off the North Downs Way at Westhumble and follow the Thames Down Link to Kingston Upon Thames (my birthplace) and get onto the Thames Path. At Banbury, you can link to the Cotswolds Way via the Cross Cotswolds Way, which would take me to Bath, and thus the Cotswolds Way to Chipping Campden. 

From Chipping Campden to Offa's Dyke Way at Sedbury is a bit of a problem, but I'll overcome that as and when I get there! From Offa's Dyke, I can join the Maelor Way at Chirk and walk over to Grindley Brook, thus connecting with Whitchurch and The Sandstone Trail to Frodsham. That's about as far as I've got so far. The Pennine Way will be another adventure altogether, as will the Coast to Coast Walk. 

Anybody out there with any ideas? The main thing is each trail, walk, link has to connect so that it is a continuous walk. :o)