For your first bird: yes, it has a pronounced supercilium, but the submoustachial stripe is very narrow (even for a meadow pipit), the base of the bill is yellow and narrow, and most importantly, it has an unbroken white eye-ring. Obviously when you're blessed with unobstructed views of the hind-claw you shouldn't ignore it.
The second bird is harder, it has some pro-Tree Pipit features such as a distinct supercilium and to a lesser extent submoustachial stripe, however, it has a very typical Meadow Pipit bill (yellow base and narrow). The lores are pale, the eye ring is unbroken. You also by no means should ignore flank streaking, apologies if that was how my messages came across, it is undoubtedly a useful feature. However, over-reliance on the feature can lead to misidentification. The hind-toe is also visible in this photo.
The white, unbroken eye ring is striking in the third bird, also note the yellow base to the bill, narrow submoustachial stripe. Yes the lores are dark, however, balanced with very blotchy flank streaking and, of course, the long hind-toe, it's clearly a Meadow Pipit. Another feature that's very useful is that there is no contrast between the white belly and the ground colour to the breast. Tree pipits are often conspicuously white bellied (in comparison to the breast).
The final bird is very typical, note the eye-ring, bill, lores, submoustachial stripe, lack of contrast in belly, blotchy flanks.
Hope this helps
