Flatland (and headwind) riding is always about W/CDA and how long you can hold it… Basically this is when us bigger and heavier guys get to have fun and mess with the mountain goats 
The advice above is good I think. Ultimately this is where absolute numbers matter eg higher the FTP and longer your TTE, the more you’ll be able to do on the front on the flats. Work on sustained tempo and SST efforts if thats the pace you are hoping to ride at in the wind and anything thats going to increase your FTP and TTE.
Of course it may be that when you hit the front you are expecting to do efforts >FTP before slotting back into the pack, and in that case you may benefit from over/unders more. My club organises a 9-up TT on a F1 racing circuit every year, and when we hit the front for a turn we are at +/- 120-140% FTP,and when we tuck back in we are probably still hitting 90% FTP for a while, so being able to clear lactate and ‘recover’ at that intensity is the key. Hence the o/u sessions and the need ultimately for a lot of z2 work to maximise mitochondria density.
Ultimately your solution will probably depend a little on how long and how hard you plan to ride on the front, but ultimately its all about big FTPs…