4 TEs is not excessive if a team does not carry a FB. Most teams nowadays use a TE as a blocking back when the situation calls for it, the so-called hybrid back or H-back. Some teams stick with single back in short yardage. Even so, the Packers carried not only the 4 TEs last season, but also Vitale for the last 5 games of the season when he was promoted from the PS along with Kumerow when Daniels and Davis went to IR.
Vitale was primarily a special teams player, taking 81 snaps on ST and 19 on offense.
By way of example, McCarthy used a variety of approaches. Here are 5 short yardage plays examples from the Carolina game in 2017 showing a variety of approaches:
https://www.packers.com/news/what-you-might-ve-missed-short-yardage-success-20014576
Two plays are single back, one has Ripkowski as the up back, and the other two have R. Rodgers and Kendricks as the up backs in a double stack with Cobb throwing some nifty cut blocks.
I don't know LaFleur's short yardage preference--single back, FB or H-back--given available talent, but for what it's worth neither the Titans in 2018 nor the Rams in 2017 or 2018 had a FB snap. This would suggest Vitale is an odd man out.
If LaFleur is inclined to use 2-back sets in short yardage, there may be a problem that secures Vitale a slot--none of the 4 TEs have demonstrated ability at that up back position. It seems like Lewis should be that guy, but if memory serves McCarthy tried him there early last season and then went away from him. Kendricks was probably the best of the bunch in that role.
If anybody has any data on LaFleur's frequency of 2-back sets last season in Tennessee, one of our PFF subscribers perhaps, that might give an indication of where this might lead.
It might or might not be revelatory that after Delanie Walker went to IR after week 1, Tennessee carried 3 TEs, Stocker, Smith and Pruitt, who played 16, 13, and 15 games respectively.
In any event, LaFluer's preferences aside, TEs in general do a lot of things--in-line block and route run, H-back in the two back sets, slot receiver, wideout receiver, special teams. You could have 3 on the field at one time in a seven man front with an H-back in short yardage. You might not have all 4 on the game day roster, but 4 on the 53 man is not necessarily too many.