Then perhaps they simply have too good veil then, needs xml adjustment.
Have there been any other tinkerings going on in these that I wasn't made aware of yet? Criminals should be just barely visible if at their best vs the best that can be pumped into the LE and Canine units. That's how I had added it up previously and that would be at a range of 1 space out so you should need to be right next to them, AND that should take into account the town/city and/or forest bonuses.
So the base formula I initially used for setup - and I'm stating this to remind myself as well is: Best Possible total of all accessible spot visibility promos and native ability for a unit should meet and thus beat the Best Possible total of all accessible veil invisibility promos + native ability + strongest potential terrain modifier totals. LE should be able to do that for disguise and dogs should be exceeding that by a few pts for criminals because strike teams and cats have the strongest camo by a point or two over criminals. This would be the main balance points I strove for along this particular contest setup and between concurrent matched upgrade stage level of criminal vs concurrent upgrade stage level of the LE units. It might be possible that the criminals briefly become impossible, at their best, to see through if they are slightly higher in upgrade rank - I think this takes place for a small time at Rogue perhaps but then this is then counterable if you aren't using town improvements for added caution. During such a stage of the game, town improvements MIGHT be islands of truly impossible to pierce invisibility levels, unless perhaps the LE units are ON those tiles with the Criminal ones trying to sneak about.
IF the levels have been tinkered with anywhere in the setup, like on promos, improvements, other tile elements, buildups, base amounts, etc, this balance point will be a bit screwed up, AND it still doesn't make it EASY to find them because this slight advantage for spotting units is only at one tile distance - even one more step out and the capped criminal can still be unseen (though that's also assuming they aren't moving and have used buildups to stay hidden so when they first move they should be visible at 2 tiles out and possibly more.)
If 'meet beats' as a rule has been changed to a tie goes to the invisible unit, then the whole thing was skewed by a pt as well... haven't reviewed the code refactorings that have taken place there recently either.
I'm not sure I ever explained how I initially setup the math but I wanted to record it for myself to be aware of as well since it's one of my next review steps is to re-review these.